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Dammann DO, Johnson MA, Fedders ER, Mahoney AR, Werner CL, Polashenski CM, Meyer FJ and Hutchings JK (2021), "Ground-Based Radar Interferometry of Sea Ice", Remote Sensing. Vol. 13(1), pp. 57-66.
Abstract: In light of recent Arctic change, there is a need to better understand sea ice dynamic processes at the floe scale to evaluate sea ice stability, deformation, and fracturing. This work investigates the use of the Gamma portable radar interferometer (GPRI) to characterize sea ice displacement and surface topography. We find that the GPRI is best suited to derive lateral surface deformation due to mm-scale horizontal accuracy. We model interferometric phase signatures from sea ice displacement and evaluate possible errors related to noise and antenna motion. We compare the analysis with observations acquired during a drifting ice camp in the Beaufort Sea. We used repeat-scan and stare-mode interferometry to identify two-dimensional shear and to track continuous uni-directional convergence. This paper demonstrates the capacity of the GPRI to derive surface strain on the order of 10−7 and identify different dynamic regions based on sub-mm changes in displacement. The GPRI is thus a promising tool for sea ice applications due to its high accuracy that can potentially resolve pre- and post-fracture deformation relevant to sea ice stability and modeling.
BibTeX:
@article{DammannEtAl2021,
  author = {Dammann, Dyre Oliver and Johnson, Mark A. and Fedders, Emily R. and Mahoney, Andrew R. and Werner, Charles L. and Polashenski, Christopher M. and Meyer, Franz J. and Hutchings, Jennifer K.},
  title = {Ground-Based Radar Interferometry of Sea Ice},
  journal = {Remote Sensing},
  year = {2021},
  volume = {13},
  number = {1},
  pages = {57-66},
  url = {https://www.mdpi.com/2072-4292/13/1/43},
  doi = {10.3390/rs13010043}
}
Peng J, Albergel C, Balenzano A, Brocca L, Cartus O, Cosh MH, Crow WT, Dabrowska-Zielinska K, Dadson S, Davidson MW, de Rosnay P, Dorigo W, Gruber A, Hagemann S, Hirschi M, Kerr YH, Lovergine F, Mahecha MD, Marzahn P, Mattia F, Musial JP, Preuschmann S, Reichle RH, Satalino G, Silgram M, van Bodegom PM, Verhoest NE, Wagner W, Walker JP, Wegmüller U and Loew A (2021), "A roadmap for high-resolution satellite soil moisture applications - confronting product characteristics with user requirements", Remote Sensing of Environment 252, 112162. Vol. 252, pp. 112162.
BibTeX:
@article{Peng2020,
  author = {Jian Peng and Clement Albergel and Anna Balenzano and Luca Brocca and Oliver Cartus and Michael H. Cosh and Wade T. Crow and Katarzyna Dabrowska-Zielinska and Simon Dadson and Malcolm W.J. Davidson and Patricia de Rosnay and Wouter Dorigo and Alexander Gruber and Stefan Hagemann and Martin Hirschi and Yann H. Kerr and Francesco Lovergine and Miguel D. Mahecha and Philip Marzahn and Francesco Mattia and Jan Pawel Musial and Swantje Preuschmann and Rolf H. Reichle and Giuseppe Satalino and Martyn Silgram and Peter M. van Bodegom and Niko E.C. Verhoest and Wolfgang Wagner and Jeffrey P. Walker and Urs Wegmüller and Alexander Loew},
  title = {A roadmap for high-resolution satellite soil moisture applications - confronting product characteristics with user requirements},
  journal = {Remote Sensing of Environment 252, 112162},
  year = {2021},
  volume = {252},
  pages = {112162},
  doi = {10.1016/j.rse.2020.112162}
}
Baffelli S, Frey O and Hajnsek I (2020), "Geostatistical Analysis and Mitigation of the Atmospheric Phase Screens in Ku-Band Terrestrial Radar Interferometric Observations of an Alpine Glacier", IEEE Transactions on Geoscience and Remote Sensing., November, 2020. Vol. 58(11), pp. 7533-7556.
Abstract: Terrestrial radar interferometry (TRI) can measure displacements at high temporal resolution, potentially with high accuracy. An application of this method is the observation of the surface flow velocity of steep, fast-flowing aglaciers. For these observations, the main factor limiting the accuracy of TRI observations is the spatial and temporal variabilities in the distribution of atmospheric water vapor content, causing a phase delay [atmospheric phase screen (APS)] whose magnitude is similar to the displacement phase. This contribution presents a geostatistical analysis of the spatial and temporal behaviors of the APS in Ku-Band TRI. The analysis is based on the assumption of a separable spatiotemporal covariance structure, which is tested empirically using variogram analysis. From this analysis, spatial and temporal APS statistics are estimated and used in a two-step procedure combining regression-Kriging with generalized least squares (GLS) inversion to estimate a velocity time-series. The performance of this method is evaluated by cross-validation using phase observations on stable scatterers. This analysis shows a considerable reduction in residual phase variance compared with the standard approach of combining the linear models of APS stratification and interferogram stacking.
BibTeX:
@article{baffelliFreyHajnsekTGRS2020GeostatisticalAtmosphereAnalysisMitigationKuBandGPRIGlacier,
  author = {Baffelli, Simone and Frey, Othmar and Hajnsek, Irena},
  title = {Geostatistical Analysis and Mitigation of the Atmospheric Phase Screens in Ku-Band Terrestrial Radar Interferometric Observations of an Alpine Glacier},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2020},
  volume = {58},
  number = {11},
  pages = {7533-7556},
  doi = {10.1109/TGRS.2020.2976656}
}
Bernet L, Brockmann E, von Clarmann T, Kämpfer N, Mahieu E, Mätzler C, Stober G and Hocke K (2020), "Trends of atmospheric water vapour in Switzerland from ground-based radiometry", FTIR and GNSS data, Atmos. Chem. Phys., 20, 11223?11244.
BibTeX:
@article{Bernet2020,
  author = {Bernet, Leonie and Brockmann, Elmar and von Clarmann, Thomas and Kämpfer, Niklaus and Mahieu, Emmanuel and Mätzler, Christian and Stober, Gunter and Hocke, Klemens},
  title = {Trends of atmospheric water vapour in Switzerland from ground-based radiometry},
  journal = {FTIR and GNSS data, Atmos. Chem. Phys., 20, 11223?11244},
  year = {2020}
}
Besnard S, Koirala S, Santoro M, Bao S, Cartus O, Gans F, Jung M, Trautmann T and Carvalhais N (2020), "Constraining carbon allocation in a terrestrial ecosystem model using long-term forest biomass time series", In EGU General Assembly 2020.. Thesis at: display., March, 2020.
Abstract: Forests cover about 30% of the terrestrial surface of our planet and store a large part of the terrestrial carbon (C), indicating their fundamental role in terrestrial C dynamics. In recent years, significant advances have been made in understanding terrestrial C cycling across scales, albeit uncertainties remain about fundamental processes, such as photosynthesis, allocation, and mortality, which exert dominant controls on vegetation C dynamics. Allocation plays a critical role in forest ecosystem C cycling by partitioning the products of net photosynthesis into leaves, wood, and below-ground components but is still poorly represented mostly given limitations in process understanding as well as in both suitable and commensurate observations.</p><p>Here, we explore different approaches in constraining C allocation alongside processes driving assimilation and out fluxes in a terrestrial ecosystem model based on novel forest biomass datasets. More specifically, we use a series of temporally changing above-ground biomass (AGB) data from local (i.e. in-situ forest inventory data) to global (i.e. long-term C-band satellite retrievals from 1992 to 2018) scales, in a multi-constraint approach. We explore the information contained in a novel AGB time series to diagnose the potential of using changes in vegetation C stocks, jointly with C and water fluxes, to constrain and parameterize different C allocation modeling approaches. Both at FLUXNET site level and global scale, we will: i) present these novel AGB datasets, their strengths and limitations, ii) demonstrate the relevance of constraining C allocation with such temporally changing AGB estimates, and iii) provide a comparison of different C allocation approaches (i.e. fixed versus dynamic allocation, and an hybrid modeling approach) and their implications in representing ecosystem dynamics.</p>
BibTeX:
@conference{Besnard2020,
  author = {Besnard, Simon and Koirala, Sujan and Santoro, Maurizio and Bao, Shanning and Cartus, Oliver and Gans, Fabian and Jung, Martin and Trautmann, Tina and Carvalhais, Nuno},
  title = {Constraining carbon allocation in a terrestrial ecosystem model using long-term forest biomass time series},
  booktitle = {EGU General Assembly 2020},
  school = {display},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-10523.html},
  doi = {10.5194/egusphere-egu2020-10523}
}
Borlaf-Mena I, Santoro M, Villard L, Badea O and Tanase MA (2020), "Investigating the Impact of Digital Elevation Models on Sentinel-1 Backscatter and Coherence Observations", Remote Sensing., September, 2020. Vol. 12(18), pp. 3016.
Abstract: Spaceborne remote sensing can track ecosystems changes thanks to continuous and systematic coverage at short revisit intervals. Active remote sensing from synthetic aperture radar (SAR) sensors allows day and night imaging as they are not a?ected by cloud cover and solar illumination and can capture unique information about its targets. However, SAR observations are a?ected by the coupled e?ect of viewing geometry and terrain topography. The study aims to assess the impact of global digital elevation models (DEMs) on the normalization of Sentinel-1 backscattered intensity and interferometric coherence. For each DEM, we analyzed the di?erence between orbit tracks, the di?erence with results obtained with a high-resolution local DEM, and the impact on land cover classi?cation. Tests were carried out at two sites located in mountainous regions in Romania and Spain using the SRTM (Shuttle Radar Topography Mission, 30 m), AW3D (ALOS (Advanced Land Observation Satellite) World 3D, 30 m), TanDEM-X (12.5, 30, 90 m), and Spain national ALS (aerial laser scanning) based DEM (5 m resolution). The TanDEM-X DEM was the global DEM most suitable for topographic normalization, since it provided the smallest di?erences between orbital tracks, up to 3.5 dB smaller than with other DEMs for peak landform, and 1.4?1.9 dB for pit and valley landforms.
BibTeX:
@article{BorlafMena2020,
  author = {Borlaf-Mena, Ignacio and Santoro, Maurizio and Villard, Ludovic and Badea, Ovidiu and Tanase, Mihai Andrei},
  title = {Investigating the Impact of Digital Elevation Models on Sentinel-1 Backscatter and Coherence Observations},
  journal = {Remote Sensing},
  year = {2020},
  volume = {12},
  number = {18},
  pages = {3016},
  url = {https://www.mdpi.com/2072-4292/12/18/3016},
  doi = {10.3390/rs12183016}
}
Caduff R, Strozzi T, Hählen N and Häberle J (2020), "Accelerating Landslide Hazard at Kandersteg, Swiss Alps; Combining 28 years of satellite InSAR and single campaign terrestrial radar data", 5th World Landslide Forum, Implementing and Monitoring the Sendai Landslide Partnerships 2015-2025, Kyoto, Japan.
BibTeX:
@article{Caduff2020,
  author = {Caduff, R. and Strozzi, T. and Hählen, N. and Häberle, J.},
  title = {Accelerating Landslide Hazard at Kandersteg, Swiss Alps; Combining 28 years of satellite InSAR and single campaign terrestrial radar data},
  journal = {5th World Landslide Forum, Implementing and Monitoring the Sendai Landslide Partnerships 2015-2025, Kyoto, Japan},
  year = {2020}
}
Fan N, Besnard S, Santoro M, Cartus O and Carvalhais N (2020), "Inferring non-steady-state terrestrial vegetation carbon turnover times from multi-decadal space-borne observations on global scale", In EGU General Assembly 2020.. Thesis at: oral., March, 2020.
Abstract: The global biomass is determined by the vegetation turnover times and carbon fixation through photosynthesis. Vegetation turnover time is a central parameter that not only partially determines the terrestrial carbon sink but also the response of terrestrial vegetation to the future changes in climate. However, the change of magnitude, spatial patterns and uncertainties in τ as well as the sensitivity of these processes to climate change is not well understood due to lack of observations on global scale. In this study, we explore a new dataset of annual above-ground biomass (AGB) change from 1993 to 2018 from spaceborne scatterometer observations. Using the long-term, spatial-explicit global dynamic dataset, we investigated how τ change over almost three decades including the uncertainties. Previous estimations of τ under steady-state assumption can now be challenged acknowledging that terrestrial ecosystems are, for the most of cases, not in balance. In this study, we explore this new dataset to derive global maps of τ in non-steady-state for different periods of time. We used a non-steady-state carbon model in which the change of AGB is a function of Gross Primary Production (GPP) and τ (ΔAGB = α*GPP-AGB/ τ). The parameter α represents the percentage of incorporation of carbon from GPP to biomass. By exploring the AGB change in 5 to 10 years of time step, we were able to infer τ and α from the observations of AGB and GPP change by solving the linear equation. We show how τ changes after potential disturbances in the early 2000s in comparison to the previous decade. We also show the spatial distributions of α from the change of AGB. By accessing the change in biomass, τ and α as well as their associated uncertainties, we provide a comprehensive diagnostic on the vegetation dynamics and the potential response of biomass to disturbance and to climate change.
BibTeX:
@conference{Fan2020a,
  author = {Fan, Naixin and Besnard, Simon and Santoro, Maurizio and Cartus, Oliver and Carvalhais, Nuno},
  title = {Inferring non-steady-state terrestrial vegetation carbon turnover times from multi-decadal space-borne observations on global scale},
  booktitle = {EGU General Assembly 2020},
  school = {oral},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-17717.html},
  doi = {10.5194/egusphere-egu2020-17717}
}
Fan N, Koirala S, Reichstein M, Thurner M, Avitabile V, Santoro M, Ahrens B, Weber U and Carvalhais N (2020), "Apparent ecosystem carbon turnover time: uncertainties and robust features", Earth Syst. Sci. Data., October, 2020. Vol. 12(4), pp. 2517-2536.
Abstract: Abstract. The turnover time of terrestrial ecosystem carbon is an emergent ecosystem property that
quantifies the strength of land surface on the global carbon cycle?climate feedback. However,
observation- and modeling-based estimates of carbon turnover and its response to climate are
still characterized by large uncertainties. In this study, by assessing the apparent whole
ecosystem carbon turnover times (?) as the ratio between carbon stocks and fluxes, we
provide an update of this ecosystem level diagnostic and its associated uncertainties in high
spatial resolution (0.083?) using multiple, state-of-the-art, observation-based datasets
of soil organic carbon stock (Csoil), vegetation biomass (Cveg)
and gross primary productivity (GPP). Using this new ensemble of data, we estimated the global
median ? to be 43-7+7?yr
(median-difference to percentile 25+difference to percentile
75) when the full soil is considered, in contrast to limiting it to 1?m
depth. Only considering the top 1?m of soil carbon in circumpolar regions (assuming
maximum active layer depth is up to 1?m) yields a global median ? of
37-6+3?yr, which is longer than the previous estimates of 23-4+7?yr
(Carvalhais et al., 2014). We show that the difference is mostly attributed to changes in global
Csoil estimates. Csoil accounts for approximately 84?% of
the total uncertainty in global ? estimates; GPP also contributes significantly
(15?%), whereas Cveg contributes only marginally (less than 1?%) to the
total uncertainty. The high uncertainty in Csoil is reflected in the large range
across state-of-the-art data products, in which full-depth Csoil spans between
3362 and 4792?PgC. The uncertainty is especially high in circumpolar regions with an
uncertainty of 50?% and a low spatial correlation between the different datasets
(0.2textlessrtextless0.5) when compared to other regions (0.6textlessrtextless0.8). These uncertainties cast a shadow
on current global estimates of ? in circumpolar regions, for which further geographical
representativeness and clarification on variations in Csoil with soil depth are
needed. Different GPP estimates contribute significantly to the uncertainties of ? mainly in
semiarid and arid regions, whereas Cveg causes the uncertainties of ? in
the subtropics and tropics. In spite of the large uncertainties, our findings reveal that the
latitudinal gradients of ? are consistent across different datasets and soil depths. The
current results show a strong ensemble agreement on the negative correlation between ? and
temperature along latitude that is stronger in temperate zones (30?60??N) than
in the subtropical and tropical zones (30??S?30??N). Additionally, while the
strength of the ??precipitation correlation was dependent on the Csoil data
source, the latitudinal gradients also agree among different ensemble members. Overall, and
despite the large variation in ?, we identified robust features in the spatial patterns of
? that emerge beyond the differences stemming from the data-driven estimates of
Csoil, Cveg and GPP. These robust patterns, and associated
uncertainties, can be used to infer ??climate relationships and for constraining
contemporaneous behavior of Earth
system models (ESMs), which could contribute to uncertainty reductions in future
projections of the carbon cycle?climate feedback. The dataset of ? is openly available at
https://doi.org/10.17871/bgitau.201911 (Fan et al., 2019).
BibTeX:
@article{Fan2020,
  author = {Fan, Naixin and Koirala, Sujan and Reichstein, Markus and Thurner, Martin and Avitabile, Valerio and Santoro, Maurizio and Ahrens, Bernhard and Weber, Ulrich and Carvalhais, Nuno},
  title = {Apparent ecosystem carbon turnover time: uncertainties and robust features},
  journal = {Earth Syst. Sci. Data},
  year = {2020},
  volume = {12},
  number = {4},
  pages = {2517--2536},
  url = {https://essd.copernicus.org/articles/12/2517/2020/},
  doi = {10.5194/essd-12-2517-2020}
}
Frey O, Werner C, Manconi A and Coscione R (2020), "Measuring surface displacements using a novel UAV/car-borne radar interferometer: including a case study on a fast-moving landslide in Brinzauls", In Swiss Geoscience Meeting 2020: Symposium 20. Remote Sensing of the Spheres. Zurich, Switzerland, November, 2020.
BibTeX:
@inproceedings{freyWernerManconiCoscioneSGM2020UAVandCARSARmobilemappingDisplacements,
  author = {Frey, Othmar and Werner, Charles and Manconi, Andrea and Coscione, Roberto},
  title = {Measuring surface displacements using a novel UAV/car-borne radar interferometer: including a case study on a fast-moving landslide in Brinzauls},
  booktitle = {Swiss Geoscience Meeting 2020: Symposium 20. Remote Sensing of the Spheres},
  year = {2020},
  url = {https://youtu.be/DxAvqFT_03I}
}
Frey O, Werner C, Manconi A and Coscione R (2020), "Mobile Mapping of Surface Displacements Using a Novel Compact UAV-Borne / Car-Borne InSAR System", In American Geophysical Union, Fall Meeting 2020.
Abstract: Flexible mobile mapping of surface displacements with repeat-pass interferometry from moving platforms such as cars and UAVs has been a rather unexplored field.
In this contribution we address this topic comprehensively: we demonstrate InSAR-based measurement of surface displacements with our novel car-borne and UAV-borne L-band SAR system setup at three different test sites in Switzerland.
The reduced temporal decorrelation at L-band is an important advantage and a complementary property as compared to high-frequency (quasi-)stationary systems. While the sensitivity to line-of-sight displacements is lower, the longer wavelength permits to acquire longer interferometric time intervals also in natural terrain and in adverse conditions, in which the decorrelation time at X- or Ku-band (the frequencies of many stationary terrestrial radar interferometers) can be in the order of minutes or less. Terrestrial synthetic aperture radar acquisitions from a car driving on a road or acquisitions from a UAV allow to obtain synthetic aperture lengths of 100m and more which yields high-resolution SAR imagery also at lower frequency such as L-band. At the same time the view geometry can be chosen to offer line-of-sight views to landslides that complement the view geometries available from spaceborne SAR systems. Then, using a time-domain back-projection image focusing approach, it is ensured that even for curvilinear paths (e.g. a car driving along a curved road) high-quality SAR images and interferograms with good spatial resolution are obtained.
Based on these properties we show that such a mobile InSAR system fills a current gap in terms of available InSAR systems for displacement monitoring.
We show the potential and discuss the challenges and the limitations of this novel InSAR-based mobile mapping system.
We do so with the help of three repeat-pass interferometry showcases (see also attached image):
1) car-borne mapping of surface displacements of fast-moving land slide and surrounding area,
2) car-borne mapping of surface displacements of a glacier,
3) UAV-borne mapping of surface displacements of a steep slope with various land covers.
The three test cases show that UAV-borne and car-borne interferometric displacement measurements at L-band are feasible with high quality over various natural terrain.
BibTeX:
@inproceedings{freyWernerManconiCoscioneAGU2020UAVandCARSARmobilemappingDisplacements,
  author = {Frey, Othmar and Werner, Charles and Manconi, Andrea and Coscione, Roberto},
  title = {Mobile Mapping of Surface Displacements Using a Novel Compact UAV-Borne / Car-Borne InSAR System},
  booktitle = {American Geophysical Union, Fall Meeting 2020},
  year = {2020},
  url = {https://agu2020fallmeeting-agu.ipostersessions.com/default.aspx?s=05-89-7D-61-8F-00-52-EE-2A-FC-13-68-68-9B-64-59}
}
Glueer F, Loew S and Manconi A (2020), "Paraglacial history and structure of the Moosfluh Landslide (1850-2016), Switzerland", Geomorphology. Vol. 355 Elsevier B.V..
Abstract: Rock slopes next to the tongue of the Great Aletsch Glacier, Switzerland are characterized by rapid environmental adjustment to non-glacial conditions. This study investigates and describes in detail the historic development of the largest rock slope instability in this area, called Moosfluh Landslide. We study in detail the structure, evolution and stability since the end of the Little Ice Age (LIA) until September 2016 and discuss their relationships with the evolution of the Great Aletsch Glacier since the Lateglacial period. In 2016 around 50 m of glacial ice thickness were left at the Moosfluh Landslide toe, where in 1850 glacial ice was >400 m thick. The changing stability conditions at the interface with the melting valley glacier are studied based on novel balanced cross sections and kinematic model of the Moosfluh Landslide dominated by toppling phenomena in metamorphic rock. The morphology and evolution of this landslide since the LIA are investigated with multi-temporal landslide maps based on aerial digital photogrammetry (ADP) applied to historic images since 1961. Internal deformation at Moosfluh is accommodated by shear slip along uphill-facing foliation and fault planes, and by extensional faulting forming tension cracks and graben-structures at the landslide head. Together with Digital Image Correlation (DIC) and total station monitoring (TPS) the Moosfluh Landslide displacement history was reconstructed, evidencing post-Egesen landslide displacements and an acceleration of movements since the LIA and especially since 2007. The displacement rates increase from few mm per year until the nineties to several meter per day in September 2016. Different kinematic models have been tested and changes in the Moosfluh rock slope stability in response to retreating glacial ice and changing groundwater conditions was explored with limit-equilibrium analysis of the stepped planar block toppling model of Goodman and Bray (1976). For the observed conditions and a toppling joint friction angle of 19° the simulated factor of safety drops non-linearly from the LIA maximum (1.12) to the year 2007 (1.02), when the height of ice above the valley bottom melted down to 100 m. This study illustrates with unprecedented detail the time scales, displacement magnitudes and structural evolutions of a large toppling mode slope instability in a paraglacial setting. The long-term cumulative slope displacements between the Egesen stadial and the LIA are of the same magnitude as the cumulative displacements between the LIA and the year 2016. As large portions of the studied slope underwent multiple retreats and advances of the Great Aletsch Glacier during the Lateglacial and Postglacial period, the observed onset of large slope displacements should be related to incremental damage (slip weakening and weathering) occurring along steeply dipping toppling fractures during the LIA. © 2019
BibTeX:
@article{Glueer2020,
  author = {Glueer, F. and Loew, S. and Manconi, A.},
  title = {Paraglacial history and structure of the Moosfluh Landslide (1850-2016), Switzerland},
  journal = {Geomorphology},
  publisher = {Elsevier B.V.},
  year = {2020},
  volume = {355},
  note = {cited By 2},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081209981&doi=10.1016%2fj.geomorph.2019.02.021&partnerID=40&md5=a8a9fdc23d4e14f27b6c95a9008389e3},
  doi = {10.1016/j.geomorph.2019.02.021}
}
Houtz D, Naderpour R and Schwank M (2020), "Portable L-Band Radiometer (PoLRa): Design and Characterization", Remote Sensing, vol. 12, no. 17, p. 2780.
BibTeX:
@article{Houtz2020,
  author = {Houtz, D. and Naderpour, R. and Schwank M.},
  title = {Portable L-Band Radiometer (PoLRa): Design and Characterization},
  journal = {Remote Sensing, vol. 12, no. 17, p. 2780},
  year = {2020}
}
Leinss S, Li S, Bernhard P and Frey O (2020), "Temporal Multi-Looking of SAR Image Series for Glacier Velocity Determination and Speckle Reduction", In EGU General Assembly 2020., May, 2020. Vol. EGU2020-3643
Abstract: The velocity of glaciers is commonly derived by offset tracking using pairwise cross correlation or feature matching of either optical or synthetic aperture radar (SAR) images. SAR images, however, are inherently affected by noise-like radar speckle and require therefore much larger images patches for successful tracking compared to the patch size used with optical data. As a consequence, glacier velocity maps based on SAR offset tracking have a relatively low resolution compared to the nominal resolution of SAR sensors. Moreover, tracking may fail because small features on the glacier surface cannot be detected due to radar speckle. Although radar speckle can be reduced by applying spatial low-pass filters (e.g. 5x5 boxcar), the spatial smoothing reduces the image resolution roughly by an order of magnitude which strongly reduces the tracking precision. Furthermore, it blurs out small features on the glacier surface, and therefore tracking can also fail unless clear features like large crevasses are visible.
In order to create high resolution velocity maps from SAR images and to generate speckle-free radar images of glaciers, we present a new method that derives the glacier surface velocity field by correlating temporally averaged sub-stacks of a series of SAR images. The key feature of the method is to warp every pixel in each SAR image according to its temporally increasing offset with respect to a reference date. The offset is determined by the glacier velocity which is obtained by maximizing the cross-correlation between the averages of two sub-stacks. Currently, we need to assume that the surface velocity is constant during the acquisition period of the image series but this assumption can be relaxed to a certain extend.
As the method combines the information of multiple images, radar speckle are highly suppressed by temporal multi-looking, therefore the signal-to-noise ratio of the cross-correlation is significantly improved. We found that the method outperforms the pair-wise cross-correlation method for velocity estimation in terms of both the coverage and the resolution of the velocity field. At the same time, very high resolution radar images are obtained and reveal features that are otherwise hidden in radar speckle.
As the reference date, to which the sub-stacks are averaged, can be arbitrarily chosen a smooth flow animation of the glacier surface can be generated based on a limited number of SAR images. The presented method could build a basis for a new generation of tracking methods as the method is excellently suited to exploit the large number of emerging free and globally available high resolution SAR image time series.
BibTeX:
@inproceedings{leinssEtAlEGU2020Stacking,
  author = {Silvan Leinss and Shiyi Li and Philipp Bernhard and Othmar Frey},
  title = {Temporal Multi-Looking of SAR Image Series for Glacier Velocity Determination and Speckle Reduction},
  booktitle = {EGU General Assembly 2020},
  year = {2020},
  volume = {EGU2020-3643},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-3643.html},
  doi = {10.5194/egusphere-egu2020-3643}
}
Li X, Al-Yaari A, Schwank M, Fan L, Frappart F, Swenson J and Wigneron J-P (2020), "Compared performances of SMOS-IC soil moisture and vegetation optical depth retrievals based on Tau-Omega and Two-Stream microwave emission models", Remote Sens. Environ.. Vol. 236 Elsevier Inc..
Abstract: Since 2010, SMOS (Soil Moisture and Ocean Salinity) retrievals of surface soil moisture (SM) and vegetation optical depth (VOD) have been produced through the inversion of the so-called Tau-Omega (TO) vegetation emission model. Tau-Omega is a 0th-order solution of the radiative transfer equations that neglects multiple scattering, conversely to 1st-order solutions as Two-Stream (2S). To date, very little is known about the compared retrieval performances of these emission models. Here, we inter-compared (SM, VOD) retrievals using the SMOS-IC algorithm running with the TO and 2S emission models. Retrieval performances obtained from TO and 2S were found to be relatively similar, except that a larger dry bias and a slightly lower SM unbiased RMSD were obtained with 2S and the VOD values of the two models vary over dense vegetation areas, both in terms of magnitude and seasonal variations. Considering this and the enhanced physical background of 2S that allows its implementation as a unified emission model for different applications, our study reveals the high interest of using Two-Stream in global retrieval algorithms at L-band. © 2019 Elsevier Inc.
BibTeX:
@article{Li2020,
  author = {Li, X. and Al-Yaari, A. and Schwank, M. and Fan, L. and Frappart, F. and Swenson, J. and Wigneron, J.-P.},
  title = {Compared performances of SMOS-IC soil moisture and vegetation optical depth retrievals based on Tau-Omega and Two-Stream microwave emission models},
  journal = {Remote Sens. Environ.},
  publisher = {Elsevier Inc.},
  year = {2020},
  volume = {236},
  note = {cited By 4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074882885&doi=10.1016%2fj.rse.2019.111502&partnerID=40&md5=7825a9214eb6c1c2b9b110698abef0f4},
  doi = {10.1016/j.rse.2019.111502}
}
Magnard C, Wegmüller U and Werner C (2020), "Persistent Scatterer Interferometry in mountainous areas: advantages of working in map geometry", SARWatch Workshop - Advances in the Science and Applications of SAR Interferometry, Vilamoura, Portugal.
BibTeX:
@article{Magnard2020,
  author = {Magnard, C. and Wegmüller, U. and Werner, C.},
  title = {Persistent Scatterer Interferometry in mountainous areas: advantages of working in map geometry},
  journal = {SARWatch Workshop - Advances in the Science and Applications of SAR Interferometry, Vilamoura, Portugal},
  year = {2020}
}
Manconi A, Caduff R, Strozzi T, Frey O, Werner. C and Wegmüller U (2020), "Monitoring displacements of complex landslide with broadband multiplatform radar techniques", Swiss Geoscience Meeting 2020: Symposium 20. Remote Sensing of the Spheres, Zurich, Switzerland.
BibTeX:
@article{Manconi2020,
  author = {Manconi, A. and Caduff, R. and Strozzi, T. and Frey, O. and Werner. C. and Wegmüller, U.},
  title = {Monitoring displacements of complex landslide with broadband multiplatform radar techniques},
  journal = {Swiss Geoscience Meeting 2020: Symposium 20. Remote Sensing of the Spheres, Zurich, Switzerland},
  year = {2020},
  url = {https://youtu.be/EEyA5MI-JpM}
}
Mialon A, Rodriguez-Fernandez NJ, Santoro M, Saatchi S, Mermoz S, Bousquet E and Kerr YH (2020), "Evaluation of the Sensitivity of SMOS L-VOD to Forest Above-Ground Biomass at Global Scale", Remote Sensing., May, 2020. Vol. 12(9), pp. 1450.
Abstract: The present study evaluates the L band Vegetation Optical Depth (L-VOD) derived from the Soil Moisture and Ocean Salinity (SMOS) satellite to monitor Above Ground Biomass (AGB) at a global scale. Although SMOS L-VOD has been shown to be a good proxy for AGB in Africa and Tropics, little is known about this relationship at large scale. In this study, we further examine this relationship at a global scale using the latest AGB maps from Saatchi et al. and GlobBiomass computed using data acquired during the SMOS period. We show that at a global scale the L-VOD from SMOS is well-correlated with the AGB estimates from Saatchi et al. and GlobBiomass with the Pearson?s correlation coefficients (R) of 0.91 and 0.94 respectively. Although AGB estimates in Africa and the Tropics are well-captured by SMOS L-VOD (R textgreater 0.9), the relationship is less straightforward for the dense forests over the northern latitudes (R = 0.32 and 0.69 with Saatchi et al. and GlobBiomass respectively). This paper gives strong evidence in support of the sensitivity of SMOS L-VOD to AGB estimates at a globale scale, providing an interesting alternative and complement to exisiting sensors for monitoring biomass evolution. These findings can further facilitate research on biomass now that SMOS is providing more than 10 years of data.
BibTeX:
@article{Mialon2020,
  author = {Mialon, Arnaud and Rodriguez-Fernandez, Nemesio J. and Santoro, Maurizio and Saatchi, Sassan and Mermoz, Stephane and Bousquet, Emma and Kerr, Yann H.},
  title = {Evaluation of the Sensitivity of SMOS L-VOD to Forest Above-Ground Biomass at Global Scale},
  journal = {Remote Sensing},
  year = {2020},
  volume = {12},
  number = {9},
  pages = {1450},
  url = {https://www.mdpi.com/2072-4292/12/9/1450},
  doi = {10.3390/rs12091450}
}
Montzka C, Cosh M, Bayat B, Bitar AA, Bindlish ABR, Bogena HR, Bolten JD, Cabot F, Caldwell T, Chan S, Colliander A, Crow W, Lannoy NDGD, Dorigo W, Evett SR, Gruber A, Hahn S, Jagdhuber T, Jones S, Kerr Y, Kim S, Koyama C, Kurum M, Lopez-Baeza E, McColl FMKA, Mecklenburg S, Mohanty B, OŃeill P, Or D, Pellarin T, Petropoulos GP, Reichle MPRH, Rodriguez-Fernandez N, Scanlon CRT, Schwartz RC, Spengler D, Suman PSS, van der Schalie R, Wegmüller WWU, Wigneron J-P, Camacho F and Nickeson J (2020), "Soil Moisture Product Validation Good Practices Protocol Version 1.0.", In Good Practices for Satellite Derived Land Product Validation (p. 123) Land Product Validation Subgroup (WGCV/CEOS).
BibTeX:
@incollection{MontzkaEtAl2020,
  author = {Carsten Montzka and Michael Cosh and Bagher Bayat and Ahmad Al Bitar and Aaron Bergand Rajat Bindlish and Heye Reemt Bogena and John D. Bolten and Francois Cabot and Todd Caldwell and Steven Chan and Andreas Colliander and Wade Crow and Narendra Dasand Gabrielle De Lannoy and Wouter Dorigo and Steven R. Evett and Alexander Gruber and Sebastian Hahn and Thomas Jagdhuber and Scott Jones and Yann Kerr and Seungbum Kim and Christian Koyama and Mehmed Kurum and Ernesto Lopez-Baeza and Francesco Mattiaand Kaighin A. McColl and Susanne Mecklenburg and Binayak Mohanty and Peggy OŃeill and Dani Or and Thierry Pellarin and George P. Petropoulos and Maria Pilesand Rolf H. Reichle and Nemesio Rodriguez-Fernandez and Christoph Rüdigerand Tracy Scanlon and Robert C. Schwartz and Daniel Spengler and Prashant Srivastavaand Swati Suman and Robin van der Schalie and Wolfgang Wagnerand Urs Wegmüller and Jean-Pierre Wigneron and Fernando Camacho and Jaime Nickeson},
  editor = {C. Montzka and M. Cosh and J. Nickeson and F. Camacho},
  title = {Soil Moisture Product Validation Good Practices Protocol Version 1.0.},
  booktitle = {Good Practices for Satellite Derived Land Product Validation (p. 123) Land Product Validation Subgroup (WGCV/CEOS)},
  year = {2020},
  doi = {10.5067/doc/ceoswgcv/lpv/sm.001}
}
Naderpour R, Houtz D and Schwank M (2020), "Snow wetness retrieved from close-range L-band radiometry in the western Greenland ablation zone", Journal of Glaciology, pp. 1-12.
BibTeX:
@article{Naderpour2020,
  author = {Naderpour, R. and Houtz, D. and Schwank, M.},
  title = {Snow wetness retrieved from close-range L-band radiometry in the western Greenland ablation zone},
  journal = {Journal of Glaciology, pp. 1-12},
  year = {2020}
}
Naesset E, McRoberts RE, Pekkarinen A, Saatchi S, Santoro M, Trier OD, Zahabu E and Gobakken T (2020), "Use of local and global maps of forest canopy height and aboveground biomass to enhance local estimates of biomass in miombo woodlands in Tanzania", Int. J. Appl. Earth Obs. Geoinf.., July, 2020. Vol. 89, pp. 102109.
Abstract: Field surveys are often a primary source of aboveground biomass (AGB) data, but plot-based estimates of parameters related to AGB are often not sufficiently precise, particularly not in tropical countries. Remotely sensed data may complement field data and thus help to increase the precision of estimates and circumvent some of the problems with missing sample observations in inaccessible areas. Here, we report the results of a study conducted in a 15,867 km� area in the dry miombo woodlands of Tanzania, to quantify the contribution of existing canopy height and biomass maps to improving the precision of canopy height and AGB estimates locally. A local and a global height map and three global biomass maps, and a probability sample of 513 inventory plots were subject to analysis. Model-assisted sampling estimators were used to estimate mean height and AGB across the study area using the original maps and then with the maps calibrated with local inventory plots. Large systematic map errors ? positive or negative ? were found for all the maps, with systematic errors as great as 60?70 %. The maps contributed nothing or even negatively to the precision of mean height and mean AGB estimates. However, after being calibrated locally, the maps contributed substantially to increasing the precision of both mean height and mean AGB estimates, with relative efficiencies (variance of the field-based estimates relative to the variance of the map-assisted estimates) of 1.3?2.7 for the overall estimates. The study, although focused on a relatively small area of dry tropical forests, illustrates the potential strengths and weaknesses of existing global forest height and biomass maps based on remotely sensed data and universal prediction models. Our results suggest that the use of regional or local inventory data for calibration can substantially increase the precision of map-based estimates and their applications in assessing forest carbon stocks for emission reduction programs and policy and financial decisions.
BibTeX:
@article{Naesset2020,
  author = {Naesset, Erik and McRoberts, Ronald E. and Pekkarinen, Anssi and Saatchi, Sassan and Santoro, Maurizio and Trier, Oivind D. and Zahabu, Eliakimu and Gobakken, Terje},
  title = {Use of local and global maps of forest canopy height and aboveground biomass to enhance local estimates of biomass in miombo woodlands in Tanzania},
  journal = {Int. J. Appl. Earth Obs. Geoinf.},
  year = {2020},
  volume = {89},
  pages = {102109},
  url = {https://linkinghub.elsevier.com/retrieve/pii/S0303243419312103},
  doi = {10.1016/j.jag.2020.102109}
}
Prakash N, Manconi A and Loew S (2020), "Mapping landslides on EO data: Performance of deep learning models vs. Traditional machine learning models", Remote Sensing. Vol. 12(3) MDPI AG.
Abstract: Mapping landslides using automated methods is a challenging task, which is still largely done using human efforts. Today, the availability of high-resolution EO data products is increasing exponentially, and one of the targets is to exploit this data source for the rapid generation of landslide inventory. Conventional methods like pixel-based and object-based machine learning strategies have been studied extensively in the last decade. In addition, recent advances in CNN (convolutional neural network), a type of deep-learning method, has been widely successful in extracting information from images and have outperformed other conventional learning methods. In the last few years, there have been only a few attempts to adapt CNN for landslide mapping. In this study, we introduce a modified U-Net model for semantic segmentation of landslides at a regional scale from EO data using ResNet34 blocks for feature extraction. We also compare this with conventional pixel-based and object-based methods. The experiment was done in Douglas County, a study area selected in the south of Portland in Oregon, USA, and landslide inventory extracted from SLIDO (Statewide Landslide Information Database of Oregon) was considered as the ground truth. Landslide mapping is an imbalanced learning problem with very limited availability of training data. Our network was trained on a combination of focal Tversky loss and cross-entropy loss functions using augmented image tiles sampled from a selected training area. The deep-learning method was observed to have a better performance than the conventional methods with an MCC (Matthews correlation coefficient) score of 0.495 and a POD (probability of detection) rate of 0.72. © 2020 by the authors.
BibTeX:
@article{Prakash2020,
  author = {Prakash, N. and Manconi, A. and Loew, S.},
  title = {Mapping landslides on EO data: Performance of deep learning models vs. Traditional machine learning models},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2020},
  volume = {12},
  number = {3},
  note = {cited By 1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080933308&doi=10.3390%2frs12030346&partnerID=40&md5=576e7e14cee58b834d8f5987a5ba45a7},
  doi = {10.3390/rs12030346}
}
Santoro M, Cartus O, Carvalhais N, Besnard S and Fan N (2020), "Forest above-ground biomass estimates across three decades from spaceborne scatterometer observations", In EGU General Assembly 2020.. Thesis at: oral., March, 2020.
Abstract: The large uncertainty characterizing the terrestrial carbon (C) cycle is a consequence of the sparse and irregular observations on the ground. In terms of observations, spaceborne remote sensing has been achieving global, repeated coverages of the Earth since the late 1970s, with a continuous increase in terms of density of observations in time and spatial resolution, thus potentially qualifying as data source to fill such gap in knowledge. Above-ground biomass is a baseline for quantifying the terrestrial C pool; however, remote sensing observations do not measure the organic mass of vegetation. Above-ground biomass (AGB) of forests can only be inferred by inverting numerical models relating and combining multiple remote sensing observations. One of the longest time record of observations from space is represented by the backscattered intensity from the European Remote Sensing Wind Scatterometer (ERS WindScat) and the MetOp Advanced Scatterometer (ASCAT), both operating at C-band (wavelength of 6 cm). An almost unbroken time series of backscatter observations at 0.25° spatial resolution exists since 1991 and data continuity is guaranteed in the next decades. In spite of the weak sensitivity of C-band backscatter to AGB, wall-to-wall estimates of AGB have been derived from high-resolution SAR observations by exploiting multiple observations acquired in a relatively short time period  (Santoro et al., Rem. Sens. Env., 2011; Santoro et al., Rem. Sens. Env., 2015). We have now applied this approach to generate a global time series of AGB estimates for each year between 1992 and 2018 from the C-band scatterometer data at 0.25° spatial resolution. The spatial patterns of AGB match known patterns from in situ records and other remote sensing datasets. The uncertainty of our AGB estimates is between 30% and 40% of the estimated value at the pixel level, providing strong confidence in multi-decadal AGB trends. We identify a constant increase of biomass across most boreal and temperate forests of the northern hemisphere. In contrast, we detect severe loss of biomass throughout the wet tropics during the 1990s and the beginning of the 2000 decade in consequence of massive deforestation. This loss in biomass is followed by a steady increase during the 2000s and the beginning of the most recent decade, coming more recently into saturation. Overall, we find that the global AGB density at 0.25° steadily increased by 9% from 71.8 Mg ha<sup>-1</sup> Pg in the 1990s to 78.1 Mg ha<sup>-1</sup> in the 2010s. Combining our AGB density estimates with the annual maps of the Climate Change Initiative (CCI) Land Cover dataset, we show that total AGB in forests decreased slightly from 566 Pg in the 1990s to 560 Pg in the 2000s, then increased to 593 Pg in the 2010s, resulting in an almost 5% net increase during the last three decades.
BibTeX:
@conference{Santoro2020a,
  author = {Santoro, Maurizio and Cartus, Oliver and Carvalhais, Nuno and Besnard, Simon and Fan, Naixin},
  title = {Forest above-ground biomass estimates across three decades from spaceborne scatterometer observations},
  booktitle = {EGU General Assembly 2020},
  school = {oral},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-19673.html},
  doi = {10.5194/egusphere-egu2020-19673}
}
Santoro M, Cartus O, Carvalhais N, Rozendaal D, Avitabilie V, Araza A, de Bruin S, Herold M, Quegan S, Rodriguez Veiga P, Balzter H, Carreiras J, Schepaschenko D, Korets M, Shimada M, Itoh T, Moreno Martinez A, Cavlovic J, Cazzolla Gatti R, da Conceicao Bispo P, Dewnath N, Labriere N, Liang J, Lindsell J, Mitchard ETA, Morel A, Pacheco Pascagaza AM, Ryan CM, Slik F, Vaglio Laurin G, Verbeeck H, Wijaya A and Willcock S (2020), "The global forest above-ground biomass pool for 2010 estimated from high-resolution satellite observations", Earth Syst. Sci. Data Discuss... Thesis at: Biosphere ? Biogeosciences.
Abstract: The terrestrial forest carbon pool is poorly quantified, in particular in regions with low forest inventory capacity. By combining multiple satellite observations of synthetic aperture radar (SAR) backscatter around the year 2010, we generated a global, spatially explicit dataset of above-ground forest biomass (dry mass, AGB) with a spatial resolution of 1?ha. Using an extensive database of 110,897 AGB measurements from field inventory plots, we show that the spatial patterns and magnitude of AGB are well captured in our map with the exception of regional uncertainties in high carbon stock forests with AGB textgreater 250?Mg?ha?1 where the retrieval was effectively based on a single radar observation. With a total global AGB of 522?Pg, our estimate of the terrestrial biomass pool in forests is lower than most estimates published in literature (426?571?Pg). Nonetheless, our dataset increases knowledge on the spatial distribution of AGB compared to the global Forest Resources Assessment (FRA) by the Food and Agriculture Organization (FAO) and highlights the impact of a country?s national inventory capacity on the accuracy of the biomass statistics reported to the FRA. We also reassessed previous remote sensing AGB maps, and identify major biases compared to inventory data, up to 120?% of the inventory value in dry tropical forests, in the sub-tropics and temperate zone. Because of the high level of detail and the overall reliability of the AGB spatial patterns, our global dataset of AGB is likely to have significant impacts on climate, carbon and socio-economic modelling schemes, and provides a crucial baseline in future carbon stock changes estimates. The dataset is available at: https://doi.pangaea.de/10.1594/PANGAEA.894711 (Santoro, 2018).
BibTeX:
@article{Santoro2020,
  author = {Santoro, Maurizio and Cartus, Oliver and Carvalhais, Nuno and Rozendaal, Danae and Avitabilie, Valerio and Araza, Arnan and de Bruin, Sytze and Herold, Martin and Quegan, Shaun and Rodriguez Veiga, Pedro and Balzter, Heiko and Carreiras, Joao and Schepaschenko, Dmitry and Korets, Mikhail and Shimada, Masanobu and Itoh, Takuya and Moreno Martinez, Alvaro and Cavlovic, Jura and Cazzolla Gatti, Roberto and da Conceicao Bispo, Polyanna and Dewnath, Nasheta and Labriere, Nicolas and Liang, Jingjing and Lindsell, Jeremy and Mitchard, Edward T. A. and Morel, Alexandra and Pacheco Pascagaza, Ana Maria and Ryan, Casey M. and Slik, Ferry and Vaglio Laurin, Gaia and Verbeeck, Hans and Wijaya, Arief and Willcock, Simon},
  title = {The global forest above-ground biomass pool for 2010 estimated from high-resolution satellite observations},
  journal = {Earth Syst. Sci. Data Discuss.},
  school = {Biosphere ? Biogeosciences},
  year = {2020},
  url = {https://essd.copernicus.org/preprints/essd-2020-148/},
  doi = {10.5194/essd-2020-148}
}
Schwaizer G, Keuris L, Nagler T, Derksen C, Luojus K, Marin C, Metsämäki S, Mudryk L, Naegeli K, Notarnicola C, Salberg A-B, Solberg R, Wiesmann A, Wunderle S, Essery R, Gustafsson D, Krinner G and Trofaier A-M (2020), "Towards a long term global snow climate data record from satellite data generated within the Snow Climate Change Initiative", In EGU General Assembly Conference Abstracts., May, 2020. , pp. 19228.
BibTeX:
@inproceedings{2020EGUGA..2219228S,
  author = {Schwaizer, Gabriele and Keuris, Lars and Nagler, Thomas and Derksen, Chris and Luojus, Kari and Marin, Carlo and Metsämäki, Sari and Mudryk, Lawrence and Naegeli, Kathrin and Notarnicola, Claudia and Salberg, Arnt-Borre and Solberg, Rune and Wiesmann, Andreas and Wunderle, Stefan and Essery, Richard and Gustafsson, David and Krinner, Gerhard and Trofaier, Anna-Maria},
  title = {Towards a long term global snow climate data record from satellite data generated within the Snow Climate Change Initiative},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2020},
  pages = {19228}
}
Soto-Navarro C, Ravilious C, Arnell A, De Lamo X, Harfoot M, Hill S, Wearn O, Santoro M, Bouvet A, Mermoz S, Le Toan T, Xia J, Liu S, Yuan W, Spawn S, Gibbs H, Ferrier S, Harwood T, Alkemade R, Schipper A, Schmidt-Traub G, Strassburg B, Miles L, Burgess N and Kapos V (2020), "Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action", Philosophical Transactions of the Royal Society B: Biological Sciences. Vol. 375(1794) Royal Society Publishing.
Abstract: Integrated high-resolution maps of carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits. A new integrated approach to biodiversity is therefore needed. Here, we (a) present a new high-resolution map of global above- and belowground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and (c) examine patterns of carbon- biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. The western Amazon Basin, Central Africa and Southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been greatly reduced are mostly found in the tropical Andes and central Sundaland. There is 38 and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12 and 21% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactness. © 2019 The Author(s) Published by the Royal Society.
BibTeX:
@article{Soto-Navarro2020,
  author = {Soto-Navarro, C. and Ravilious, C. and Arnell, A. and De Lamo, X. and Harfoot, M. and Hill, S.L.L. and Wearn, O.R. and Santoro, M. and Bouvet, A. and Mermoz, S. and Le Toan, T. and Xia, J. and Liu, S. and Yuan, W. and Spawn, S.A. and Gibbs, H.K. and Ferrier, S. and Harwood, T. and Alkemade, R. and Schipper, A.M. and Schmidt-Traub, G. and Strassburg, B. and Miles, L. and Burgess, N.D. and Kapos, V.},
  title = {Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action},
  journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
  publisher = {Royal Society Publishing},
  year = {2020},
  volume = {375},
  number = {1794},
  note = {cited By 2},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078349717&doi=10.1098%2frstb.2019.0128&partnerID=40&md5=ede27fe9884dcc8e7952514ab6e781be},
  doi = {10.1098/rstb.2019.0128}
}
Strozzi T, Caduff R, Jones N, Barboux C, Delaloye R, Bodin X, Kääb A, Mätzler E and Schrott L (2020), "Monitoring rock glacier kinematics with satellite synthetic aperture radar", Remote Sensing. Vol. 12(3) MDPI AG.
Abstract: Active rock glaciers represent the best visual expression of mountain permafrost that can be mapped and monitored directly using remotely sensed data. Active rock glaciers are bodies that consist of a perennially frozen ice/rock mixture and express a distinct flow-like morphology indicating downslope permafrost creep movement. Annual rates of motion have ranged from a few millimeters to several meters per year, varying within the annual cycle, from year to year, as well as at the decennial time scale. During the last decade, in situ observations in the European Alps have shown that active rock glaciers are responding almost synchronously to inter-annual and decennial changes in ground temperature, suggesting that the relative changes of their kinematics are a general indicator of the evolution of mountain permafrost conditions. Here, we used satellite radar interferometry (InSAR) to monitor the rate of motion of various active rock glaciers in the Swiss Alps, Qeqertarsuaq (Western Greenland), and the semiarid Andes of South America. Velocity time series computed with Sentinel-1 SAR images, regularly acquired since 2014, every six days over Europe and Greenland and every 12 days over the Andes, show annual fluctuations, with higher velocities at the end of the summer. A JERS-1 image pair of 1996 and stacks of very high-resolution SAR images from TerraSAR-X and Cosmo-SkyMed from 2008 to 2017 were analyzed using InSAR and offset tracking over the Western Swiss Alps in order to extend the main observation period of our study. A quantitative assessment of the accuracy of InSAR and offset tracking was performed by comparison with in situ methods. Our results for the three different study regions demonstrate that Sentinel-1 InSAR can complement worldwide in situ measurements of active rock glacier kinematics. © 2020 by the authors.
BibTeX:
@article{Strozzi2020,
  author = {Strozzi, T. and Caduff, R. and Jones, N. and Barboux, C. and Delaloye, R. and Bodin, X. and Kääb, A. and Mätzler, E. and Schrott, L.},
  title = {Monitoring rock glacier kinematics with satellite synthetic aperture radar},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2020},
  volume = {12},
  number = {3},
  note = {cited By 0},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080895862&doi=10.3390%2frs12030559&partnerID=40&md5=9ab0d7ddff51f0f3b527b52503ea958e},
  doi = {10.3390/rs12030559}
}
Strozzi T, Caduff R, Manconi A, Wegmüller U and Ambrosi C (2020), "Monitoring slow-moving landslides in Switzerland with satellite SARinterferometry", Swiss Bulletin für angewandte Geologie.
BibTeX:
@article{Strozzi2020a,
  author = {Strozzi, T. and Caduff, R. and Manconi, A. and Wegmüller, U. and Ambrosi, C.},
  title = {Monitoring slow-moving landslides in Switzerland with satellite SARinterferometry},
  journal = {Swiss Bulletin für angewandte Geologie},
  year = {2020}
}
Strozzi T, Carreon-Freyre D and Wegmüller U (2020), "Land subsidence andassociated ground fracturing: study cases in central Mexico with ALOS-2 PALSAR-2 ScanSAR Interferometry", Proc. IAHS Tenth InternationalSymposium on Land Subsidence (TISOLS), 382, 179-182.
BibTeX:
@article{Strozzi2020c,
  author = {Strozzi, T. and Carreon-Freyre, D. and Wegmüller, U.},
  title = {Land subsidence andassociated ground fracturing: study cases in central Mexico with ALOS-2 PALSAR-2 ScanSAR Interferometry},
  journal = {Proc. IAHS Tenth InternationalSymposium on Land Subsidence (TISOLS), 382, 179-182},
  year = {2020}
}
Su Z, Wen J, Zeng Y, Zhao H, Lv S, van der Velde R, Zheng D, Wang X, Wang Z, Schwank M, Kerr Y, Yueh S, Colliander A, Qian H, Drusch M and Mecklenburg S (2020), "Multiyear in-situ L-band microwave radiometry of land surface processes on the Tibetan Plateau", Scientific Data, vol. 7, no. 1, p. 317.
BibTeX:
@article{Su2020,
  author = {Su, Z. and Wen, J. and Zeng, Y. and Zhao, H. and Lv, S. and van der Velde, R. and Zheng, D. and Wang, X. and Wang, Z. and Schwank, M. and Kerr, Y. and Yueh, S. and Colliander, A. and Qian, H. and Drusch, M. and Mecklenburg, S.},
  title = {Multiyear in-situ L-band microwave radiometry of land surface processes on the Tibetan Plateau},
  journal = {Scientific Data, vol. 7, no. 1, p. 317},
  year = {2020}
}
Tosi L, Da Lio S, Donnici C, Strozzi T and Teatini P (2020), "Vulnerability of Venice's coastland to relative sea-level rise", Proc. IAHS Tenth International Symposium on Land Subsidence (TISOLS) 382,689-695.
BibTeX:
@article{Tosi2020,
  author = {Tosi, L. and Da Lio, S. and Donnici, C. and Strozzi, T. and Teatini, P.},
  title = {Vulnerability of Venice's coastland to relative sea-level rise},
  journal = {Proc. IAHS Tenth International Symposium on Land Subsidence (TISOLS) 382,689-695},
  year = {2020}
}
Wegmüller U, Caduff R and Strozzi T (2020), "Einsatz von Radarmethoden im Geomonitoring der Schweiz", Tagungsband Geomonitoring 2020, S. 3-15.
BibTeX:
@article{Wegmuller2020,
  author = {Wegmüller, U. and Caduff, R. and Strozzi, T.},
  title = {Einsatz von Radarmethoden im Geomonitoring der Schweiz},
  journal = {Tagungsband Geomonitoring 2020, S. 3-15},
  year = {2020}
}
Wegmüller U, Magnard C, Werner C, Strozzi T, Caduff R and Manconi A (2020), "Methods to avoid being affected by non-zero closure phase in InSAR time series analysis in a multi-reference stack", SARWatch Workshop - Advances in the Science and Applications of SAR Interferometry, Vilamoura, Portugal.
BibTeX:
@article{Wegmuller2020a,
  author = {Wegmüller, Urs and Magnard, Christophe and Werner, Charles and Strozzi, Tazio and Caduff, Rafael and Manconi, Andrea},
  title = {Methods to avoid being affected by non-zero closure phase in InSAR time series analysis in a multi-reference stack},
  journal = {SARWatch Workshop - Advances in the Science and Applications of SAR Interferometry, Vilamoura, Portugal},
  year = {2020}
}
Yang H, Ciais P, Santoro M, Huang Y, Li W, Wang Y, Bastos A, Goll D, Arneth A, Anthoni P, Arora VK, Friedlingstein P, Harverd V, Joetzjer E, Kautz M, Lienert S, Nabel JEMS, O'Sullivan M, Sitch S, Vuichard N, Wiltshire A and Zhu D (2020), "Comparison of forest above-ground biomass from dynamic global vegetation models with spatially explicit remotely sensed observation-based estimates", Global Change Biol.., July, 2020. Vol. 26(7), pp. 3997-4012.
BibTeX:
@article{Yang2020,
  author = {Yang, Hui and Ciais, Philippe and Santoro, Maurizio and Huang, Yuanyuan and Li, Wei and Wang, Yilong and Bastos, Ana and Goll, Daniel and Arneth, Almut and Anthoni, Peter and Arora, Vivek K. and Friedlingstein, Pierre and Harverd, Vanessa and Joetzjer, Emilie and Kautz, Markus and Lienert, Sebastian and Nabel, Julia E. M. S. and O'Sullivan, Michael and Sitch, Stephen and Vuichard, Nicolas and Wiltshire, Andy and Zhu, Dan},
  title = {Comparison of forest above-ground biomass from dynamic global vegetation models with spatially explicit remotely sensed observation-based estimates},
  journal = {Global Change Biol.},
  year = {2020},
  volume = {26},
  number = {7},
  pages = {3997--4012},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15117},
  doi = {10.1111/gcb.15117}
}
Zheng D, Li X, Zhao T, Wen J, Van Der Velde R, Schwank M, Wang X, Wang Z and Su Z (2020), "Impact of Soil Permittivity and Temperature Profile on L-Band Microwave Emission of Frozen Soil", IEEE Trans. Geosci. Remote Sens.. , pp. 1-14. Institute of Electrical and Electronics Engineers (IEEE).
BibTeX:
@article{Zheng2020,
  author = {Zheng, D. and Li, X. and Zhao, T. and Wen, J. and Van Der Velde, R. and Schwank, M. and Wang, X. and Wang, Z. and Su, Z.},
  title = {Impact of Soil Permittivity and Temperature Profile on L-Band Microwave Emission of Frozen Soil},
  journal = {IEEE Trans. Geosci. Remote Sens.},
  publisher = {Institute of Electrical and Electronics Engineers (IEEE)},
  year = {2020},
  pages = {1--14},
  doi = {10.1109/TGRS.2020.3024971}
}
Baffelli S, Frey O and Hajnsek I (2019), "Polarimetric analysis of natural terrain observed with a ku-band terrestrial radar", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 12(12), pp. 5268-5288. Institute of Electrical and Electronics Engineers.
Abstract: Terrestrial radar interferometers (TRI) are complimentary to spaceborne synthetic aperture radar systems for deformation monitoring in natural terrain: They permit shorter revisit times and greater flexibility in acquisition mode and timing. The additional diversity offered by polarimetric data can also be beneficial for TRI observations because polarized waves are sensitive to the dielectric and geometrical properties of the scatterers. Polarimetric data helps to distinguish different scattering mechanisms in a resolution cell while at the same time estimating terrain displacements. However, the polarimetric scattering signatures of natural surfaces at Ku-Band are not as well characterized as the ones at longer wavelengths, owing to relative rarity of full polarimetric systems operating in Ku-band. This band is often employed in TRI to obtain a fine azimuth resolution with a limited aperture size. This article aims at assessing the potential of polarimetric measurements in Ku-band TRI through an experimental study of polarimetric scattering signatures of natural surfaces using two datasets acquired over a glacier and in an agricultural and urban scene. The main finding of this analysis is that the Cloude-Pottier entropy is high for all land cover types; it is only observed to be less than 0.5 for scatterers with a large radar cross section. Several plausible hypotheses for this observation are formulated and tested, the most likely assumes a combination of depolarizing scattering from natural surfaces and the effect of the large ratio of wavelength to resolution cell size.
BibTeX:
@article{Baffelli20195268,
  author = {Baffelli, S. and Frey, O. and Hajnsek, I.},
  title = {Polarimetric analysis of natural terrain observed with a ku-band terrestrial radar},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2019},
  volume = {12},
  number = {12},
  pages = {5268-5288},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85079352718&doi=10.1109%2fJSTARS.2019.2953206&partnerID=40&md5=5a80f6a1d5c74ee9af3abb50507afcf5},
  doi = {10.1109/JSTARS.2019.2953206}
}
Bartsch A, Leibman M, Strozzi T, Khomutov A, Widhalm B, Babkina E, Mullanurov D, Ermokhina K, Kroisleitner C and Bergstedt H (2019), "Seasonal progression of ground displacement identified with satellite radar interferometry and the impact of unusually warm conditions on permafrost at the Yamal Peninsula in 2016", Remote Sensing. Vol. 11(16) MDPI AG.
Abstract: Ground subsidence monitoring by Synthetic Aperture Radar interferometry (InSAR) over Arctic permafrost areas is largely limited by long revisit intervals, which can lead to signal decorrelation. Recent satellite missions such as COSMO-Skymed (X-band) and Sentinel-1 (C-band) have comparably short time intervals of a few days. We analyze dense records of COSMO-Skymed from 2013 and 2016 and of Sentinel-1 from 2016, 2017, and 2018 for the unfrozen period over central Yamal (Russia). These years were distinct in environmental conditions and 2016 in particular was unusually warm. We evaluate the InSAR-derived displacement with in situ subsidence records, active-layer thickness measurements, borehole temperature records, meteorological data, C-band scatterometer records, and a land-cover classification based on Sentinel-1 and -2 data. Our results indicate that a comparison of seasonal thaw evolution between years is feasible after accounting for the early thaw data gap in InSAR time series (as a result of snow cover) through an assessment with respect to degree-days of thawing. Average rates of subsidence agree between in situ and Sentinel-1 (corrected for viewing geometry), with 3.9mmand 4.3mmper 100 degree-days of thaw at the test site. X-band and C-band records agree well with each other, including seasonal evolution of subsidence. The average displacement is more than twice in magnitude at the active-layer monitoring test site in 2016 compared to the other years. We further demonstrate that InSAR displacement can not only provide information on the magnitude of ground thaw but also on soil properties through analyses of seasonal evolution in extreme years. 2019 by the authors.
BibTeX:
@article{Bartsch2019,
  author = {Bartsch, A. and Leibman, M. and Strozzi, T. and Khomutov, A. and Widhalm, B. and Babkina, E. and Mullanurov, D. and Ermokhina, K. and Kroisleitner, C. and Bergstedt, H.},
  title = {Seasonal progression of ground displacement identified with satellite radar interferometry and the impact of unusually warm conditions on permafrost at the Yamal Peninsula in 2016},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2019},
  volume = {11},
  number = {16},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071529516&doi=10.3390%2frs11161865&partnerID=40&md5=6c0363c29af2d07e74c2d86782f6032c},
  doi = {10.3390/rs11161865}
}
Bickel V, Lanaras C, Manconi A, Loew S and Mall U (2019), "Automated Detection of Lunar Rockfalls Using a Convolutional Neural Network", IEEE Transactions on Geoscience and Remote Sensing. Vol. 57(6), pp. 3501-3511. Institute of Electrical and Electronics Engineers Inc..
Abstract: This paper implements a novel approach to automatically detect and classify rockfalls in Lunar Reconnaissance Orbiter narrow angle camera (NAC) images using a single-stage dense object detector (RetinaNet). The convolutional neural network has been trained with a data set of 2932 original rockfall images. In order to avoid overfitting, the initial training data set has been augmented during training using random image rotation, scaling, and flipping. Testing images have been labelled by human operators and have been used for RetinaNet performance evaluation. Testing shows that RetinaNet is capable to reach recall values between 0.98 and 0.39, precision values between 1 and 0.25, and average precisions ranging from 0.89 to 0.69, depending on the used confidence threshold and intersection-over-union values. Mean processing time of a single NAC image in RetinaNet is around 10 s using a GeForce GTX 1080 Ti and GeForce Titan Xp, which is in orders of magnitudes faster than a human operator. The processing speed allows to efficiently exploit the currently available NAC data stack with more than 1 million images in a reasonable timeframe. The combination of speed and detection performance can be used to produce lunar rockfall distribution maps on large spatial scales for utilization by the scientific and engineering community.
BibTeX:
@article{Bickel20193501,
  author = {Bickel, V.T. and Lanaras, C. and Manconi, A. and Loew, S. and Mall, U.},
  title = {Automated Detection of Lunar Rockfalls Using a Convolutional Neural Network},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  volume = {57},
  number = {6},
  pages = {3501-3511},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058993727&doi=10.1109%2fTGRS.2018.2885280&partnerID=40&md5=084e4ce5571a8cede066c26b3dc2d38f},
  doi = {10.1109/TGRS.2018.2885280}
}
Bueechi E, Klimes J, Frey H, Huggel C, Strozzi T and Cochachin A (2019), "Regional-scale landslide susceptibility modelling in the Cordillera Blanca, Peru - a comparison of different approaches", Landslides. Vol. 16(2), pp. 395-407. Springer Verlag.
Abstract: This study applied existing methods of landslide susceptibility modelling of the mountainous area of the Cordillera Blanca (Peru), which is prone to landslides. In heterogeneous regions as in the Cordillera Blanca, the performance of a physically based approach Stability Index Mapping (SINMAP) was compared to empirical statistical models using logistic regression and a landslide density model. All models were applied to three different digital elevation models (DEMs): ASTER GDEM, SRTM (both 30-m spatial resolution), and TanDEM-X (12-m spatial resolution). Obtained results were evaluated using the area under the receiver operating characteristic curve (AUC) approach, once for a landslide inventory which extends over the whole study area and once using an inventory of a smaller area. The physically based approach (AUCs between 0.567 and 0.625) performed worse than the statistical models (AUCs from 0.672 to 0.759) over the large area. Additionally, all models received higher performances within the small area. This coincided with differences of the variability of the DEM-derived characteristics (e.g. slope angle and curvature) from the small to the large evaluation area. Using the smaller evaluation area, all models received higher AUC values (0.743–0.799), and the impact of the DEMs was less visible. The analysis of the susceptibility showed that mainly the same slopes are considered as most or least susceptible by all models, but SINMAP is classifying larger areas as unstable or stable. Overall, this study showed that regional-scale landslide susceptibility modelling can lead to reasonable results even in regions with scarce model input data, but performances of different DEMs and models need to be evaluated carefully. 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
BibTeX:
@article{Bueechi2019395,
  author = {Bueechi, E. and Klimes, J. and Frey, H. and Huggel, C. and Strozzi, T. and Cochachin, A.},
  title = {Regional-scale landslide susceptibility modelling in the Cordillera Blanca, Peru - a comparison of different approaches},
  journal = {Landslides},
  publisher = {Springer Verlag},
  year = {2019},
  volume = {16},
  number = {2},
  pages = {395-407},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055695245&doi=10.1007%2fs10346-018-1090-1&partnerID=40&md5=130082890be85257fe6feebdfd6ff99b},
  doi = {10.1007/s10346-018-1090-1}
}
Cartus O and Santoro M (2019), "Exploring combinations of multi-temporal and multi-frequency radar backscatter observations to estimate above-ground biomass of tropical forest", Remote Sensing of Environment. Vol. 232 Elsevier Inc..
Abstract: Approaches exploiting the complementary information on forest above-ground biomass (AGB) contained in multi-temporal and multi-frequency radar backscatter have hardly been explored in the tropics. Having available a multi-seasonal stack of air- and spaceborne X-, C-, L-, and P-band imagery for forest sites in Lope and Mondah, Gabon, we analyzed the sensitivity of backscatter at different frequencies to AGB under varying environmental imaging conditions, and the performance of an AGB retrieval when combining multi-temporal and multi-frequency backscatter observations. For the tropical forest sites in Gabon, which differ significantly with respect to forest composition and climatic conditions, we find that i) P-band allows for estimating AGB with the highest accuracy, ii) multi-temporal L-band backscatter may achieve accuracies close to what can be achieved with few P-band observations, iii) the use of multi-temporal observations is beneficial/crucial at all frequencies, in particular when the imaging conditions are persistently moist and the sensitivity of individual images to AGB reduced, and iv) combining P- and L-band backscatter allows for improving the AGB retrieval primarily when few P-band observations are complemented by a larger number of L-band observations. While the results of this study reemphasize that P-band is the most suitable frequency for mapping AGB in the tropics, they also advise consideration of the growing archives of spaceborne backscatter observations acquired at higher frequencies when mapping AGB in the tropics. 2019 Elsevier Inc.
BibTeX:
@article{Cartus2019a,
  author = {Cartus, O. and Santoro, M.},
  title = {Exploring combinations of multi-temporal and multi-frequency radar backscatter observations to estimate above-ground biomass of tropical forest},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2019},
  volume = {232},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85069974980&doi=10.1016%2fj.rse.2019.111313&partnerID=40&md5=d0055171bde32f798eeb3b83ba796ab9},
  doi = {10.1016/j.rse.2019.111313}
}
Cartus O, Santoro M, Wegmüller U and Rommen B (2019), "Benchmarking the retrieval of biomass in boreal forests using P-band SAR backscatter with multi-temporal C- and L-band observations", Remote Sensing. Vol. 11(14) MDPI AG.
Abstract: The planned launch of a spaceborne P-band radar mission and the availability of C- and L-band data from several spaceborne missions suggest investigating the complementarity of C-, L-, and P-band backscatter with respect to the retrieval of forest above-ground biomass. Existing studies on the retrieval of biomass with multi-frequency backscatter relied on single observations of the backscatter and were thus not able to demonstrate the potential of multi-temporal C- and L-band data that are now available from spaceborne missions. Based on spaceborne C- and L-band and airborne P-band images acquired over a forest site in southern Sweden, we investigated whether Cand L-band backscatter may complement retrievals of above-ground biomass from P-band. To this end, a retrieval framework was adopted that utilizes a semi-empirical model for C- and L-bands and an empirical parametric model for P-band. Estimates of above-ground biomass were validated with the aid of 20 m-diameter plots and a LiDAR-derived biomass map with 100 m × 100 m pixel size. The highest retrieval accuracy when not combining frequencies was obtained for P-band with a relative root mean square error (RMSE) of 30% at the hectare scale. The retrieval with multi-temporal L- and C-bands produced errors of the order of 40% and 50%, respectively. The P-band retrieval could be improved for 4% when using P-, L-, and C-bands jointly. The combination of C- and L-bands allowed for retrieval accuracies close to those achieved with P-band. A crucial requirement for achieving an error of 30% with C- and L-bands was the use of multi-temporal observations, which was highlighted by the fact that the retrieval with the best individual L-band image was associated with an error of 61%. The results of this study reconfirmed that P-band is the most suited frequency for the retrieval of above-ground biomass of boreal forests based on backscatter, but also highlight the potential of multi-temporal C- and L-band imagery for mapping above-ground biomass, for instance in areas where the planned ESA BIOMASS P-band mission will not be allowed to acquire data. 2019 by the authors.
BibTeX:
@article{Cartus2019b,
  author = {Cartus, O. and Santoro, M. and Wegmüller, U. and Rommen, B.},
  title = {Benchmarking the retrieval of biomass in boreal forests using P-band SAR backscatter with multi-temporal C- and L-band observations},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2019},
  volume = {11},
  number = {14},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071575637&doi=10.3390%2frs11141695&partnerID=40&md5=8610d5a6340abbe0b1cfedb98f2698cc},
  doi = {10.3390/rs11141695}
}
Coscione R, Hajnsek I and Frey O (2019), "Trajectory Uncertainty in Repeat-Pass SAR Interferometry: A Case Study", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 338-341. Institute of Electrical and Electronics Engineers Inc..
Abstract: In the context of differential synthetic aperture radar interferometry (DInSAR), precise trajectory estimation of the SAR platform is necessary to minimize residual phase errors induced by inaccurate knowledge of the 3D acquisition geometry.Inertial navigation systems (INS) and global navigation satellite system (GNSS) are usually employed to track the position of the platform. However, their unavoidable inaccuracies lead to motion estimation errors that negatively affect the quality of the processed radar data.To assess the positioning performance in a repeat-pass scenario, we used a navigation-grade INS/GNSS system to preciselytrack the position and the attitude of a platform moving along a rail and carrying a SAR sensor. We analyse the performance of the positioning solution for different scenarios relevant to repeat-pass DInSAR. since the position of the platform is nearly perfectly repeated at every pass (zero interferometric baseline), the precision of the estimated position can be assessed and the interferometric performance evaluated. 2019 IEEE.
BibTeX:
@conference{Coscione2019338,
  author = {Coscione, R. and Hajnsek, I. and Frey, O.},
  title = {Trajectory Uncertainty in Repeat-Pass SAR Interferometry: A Case Study},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {338-341},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077693695&doi=10.1109%2fIGARSS.2019.8898809&partnerID=40&md5=bd5321b8343f8933b70d8041ba546edd},
  doi = {10.1109/IGARSS.2019.8898809}
}
Dini B, Daout S, Manconi A and Loew S (2019), "Classification of slope processes based on multitemporal DInSAR analyses in the Himalaya of NW Bhutan", Remote Sensing of Environment. Vol. 233 Elsevier Inc..
Abstract: Slope deformation in mountainous terrain can be driven by different processes, the nature of which is either gravitational and irreversible or seasonal and reversible, the latter induced by permafrost variations or by hydromechanical or thermomechanical effects. The importance of identifying such deformations is not only related to the hazard they can pose, but also to the understanding of changes that permafrost or local hydrological conditions undergo. Here, we carry out a multi-temporal InSAR analysis over a mountainous area 8000 km2 large, straddling north-western Bhutan and southern Tibet. We propose a methodology to separate locally deforming areas from the effects of long-wavelength signals through the analysis of the spatio-temporal behaviour of 4-years long time series of surface displacements. We present the mapping of hundreds of small-scale features that appear to be actively deforming, as well as several examples of reversible deformation rarely detected at this scale in such a challenging and vast region. The analysis of the multi-annual trend of ground deformation shows a relatively small number of irreversible gravitational movements clearly related to rock slides which attests a low level of recent activity of large rock slope instabilities in the region. In the southernmost, lower elevation parts of the study area, we quantify reversible surface displacements with amplitudes ranging between 5 and 17 mm, and showing maximum displacements towards the satellite in summer months, thus compatible with hydro-mechanical effects related to groundwater table variations. In addition, the ground movement induced by the active layer's response to thawing and freezing over the gentler slopes and high-elevation permafrost regions of Bhutan and southern Tibet is on average around 10 mm, with maxima up to 28 mm. The localised displacements appear to be largely associated to braided stream plains, glacier outwash plains or low angle, fine sediment covered slopes. 2019 Elsevier Inc.
BibTeX:
@article{Dini2019,
  author = {Dini, B. and Daout, S. and Manconi, A. and Loew, S.},
  title = {Classification of slope processes based on multitemporal DInSAR analyses in the Himalaya of NW Bhutan},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2019},
  volume = {233},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071919212&doi=10.1016%2fj.rse.2019.111408&partnerID=40&md5=4ee4298b425040fb70ba0dacc43f8e13},
  doi = {10.1016/j.rse.2019.111408}
}
Dini B, Manconi A and Loew S (2019), "Investigation of slope instabilities in NW Bhutan as derived from systematic DInSAR analyses", Engineering Geology. Vol. 259 Elsevier B.V..
Abstract: In this work we present a methodology based on remote sensing data to map and classify unstable slopes in high alpine areas and apply this methodology to the Himalaya of northwestern Bhutan. We leverage on radar images acquired by the ESA Envisat and the JAXA ALOS-1 satellites between 2007 and 2011. Synthetic aperture radar differential interferometry (DInSAR) is used to identify and quantify recent ground surface displacements associated with potentially unstable slopes. Optical satellite images and a high-resolution digital surface model is used for the geomorphological classification of individual landforms and deposits associated with displacements. The analysis of the geomorphological characteristics reveals that displacements are associated with: rock slides, mountain slope deformation and rock slope deformation (77.5%), soil creep (4%), soil slides (1.9%) and rock glaciers (12.3%); 4.3% of the detected displacements remain of unknown origin. The method applied here for the assessment of activity likelihood uses a very large number of interferograms obtained with images acquired by different satellites. The method, which is new and replicable, takes advantage of the combination of different acquisition geometries and then combines indices of vegetation cover, layover, velocity estimate and temporal sampling associated with each detected active area to assign a weight. The analysis shows that a cluster of unstable slopes exists in the northwest, potentially related to the presence of an important regional lineament and the distribution of permafrost. Comparatively little ongoing activity is detected in the south, but field validation documents substantial landslide activity in the recent geological past. The dataset here generated, containing 700 potentially unstable areas with an associated activity likelihood, is a novel dataset that makes an essential basis of future analysis to investigate rock slope instability distribution and predisposing factors. Moreover, this dataset represents a new important step towards future landslide hazard assessment in the Himalaya of Bhutan. 2019
BibTeX:
@article{Dini2019b,
  author = {Dini, B. and Manconi, A. and Loew, S.},
  title = {Investigation of slope instabilities in NW Bhutan as derived from systematic DInSAR analyses},
  journal = {Engineering Geology},
  publisher = {Elsevier B.V.},
  year = {2019},
  volume = {259},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067296350&doi=10.1016%2fj.enggeo.2019.04.008&partnerID=40&md5=a7506c435cd89e3eb2f427802ef824cb},
  doi = {10.1016/j.enggeo.2019.04.008}
}
Frey O, Werner C and Coscione R (2019), "Car-borne and UAV-borne mobile mapping of surface displacements with a compact repeat-pass interferometric SAR system at L-band", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 274-277. Institute of Electrical and Electronics Engineers Inc..
Abstract: In this paper, we present first results of car-borne and UAV-borne mobile mapping of potential surface displacements with a compact repeat-pass interferometric FMCW SAR system at L-band: (1) glacier-flow-induced displacements were measured at Stein glacier in the Swiss alps in car-borne mode along a slightly curved road section; (2) a valley slope was observed repeatedly using the vertical-take-off-and-landing (VTOL) UAV Scout B1-100 flown by Aeroscout. The SAR raw data were focused directly to an image grid in map coordinates, involving a digital elevation model and accurate GNSS/INS navigation data, by using a time-domain back-projection (TDBP) approach. These geocoded complex SAR images then allow to directly form differential interferograms in map coordinates. The feasibility of repeat-pass interferometry using our novel FMCW L-band SAR on mobile platforms such as a car or a UAV is successfully demonstrated with several data examples.
BibTeX:
@conference{Frey2019274,
  author = {Frey, O. and Werner, C.L. and Coscione, R.},
  title = {Car-borne and UAV-borne mobile mapping of surface displacements with a compact repeat-pass interferometric SAR system at L-band},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {274-277},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077719480&doi=10.1109%2fIGARSS.2019.8897827&partnerID=40&md5=2fb5be58d77f5074a24f7b34db05dd5f},
  doi = {10.1109/IGARSS.2019.8897827}
}
Glueer F, Loew S, Manconi A and Aaron J (2019), "From Toppling to Sliding: Progressive Evolution of the Moosfluh Landslide, Switzerland", Journal of Geophysical Research: Earth Surface. Vol. 124(12), pp. 2899-2919. Blackwell Publishing Ltd.
Abstract: This paper presents a detailed analysis of a dramatic rock slope acceleration that occurred in fall 2016 at the Moosfluh Landslide, located at the glacier tongue of the Great Aletsch Glacier (Switzerland). The acceleration that occurred in 2016 was unanticipated and exposed the valley bottom and an adjacent damned lake to high risk. This acceleration occurred in an active deep-seated gravitational slope deformation (DSGSD) controlled primarily by deep block-flexural toppling. In 2013, a highly accurate displacement monitoring system was developed and installed in the surroundings of the Great Aletsch Glacier, including a time-lapse camera, GNSS, and robotic total stations. This monitoring system provided unique data during the 2016 slope acceleration which are used in this study to assess failure mechanisms, landslide volumes, and subsurface displacement geometry. Based on a novel displacement vector analysis, we find that three retrogressive secondary rockslides developed during the first six weeks of the slope acceleration, with rupture surface depths of 30 to 40 m, and estimated volumes between 1 and 4 Mm3. These rockslides display complex deformation features, including head and lateral scarps, which developed during the slope acceleration. The kinematics of these secondary rockslides changed through time, from primarily toppling to combined toppling and sliding. Our results provide a uniquely detailed understanding of the spatial and temporal evolution of deformation features and movement kinematics that occur when several sectors of a slowly moving DSGSD transitions into rapid rockslides. 2019. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Glueer20192899,
  author = {Glueer, F. and Loew, S. and Manconi, A. and Aaron, J.},
  title = {From Toppling to Sliding: Progressive Evolution of the Moosfluh Landslide, Switzerland},
  journal = {Journal of Geophysical Research: Earth Surface},
  publisher = {Blackwell Publishing Ltd},
  year = {2019},
  volume = {124},
  number = {12},
  pages = {2899-2919},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076403241&doi=10.1029%2f2019JF005019&partnerID=40&md5=8fa8e89fdd5671bfbff5496469cc4e56},
  doi = {10.1029/2019JF005019}
}
Hocke K, Bernet L, Hagen J, Murk A, Renker M and Matzler C (2019), "Diurnal cycle of short-term fluctuations of integrated water vapour above Switzerland", Atmospheric Chemistry and Physics. Vol. 19(19), pp. 12083-12090. Copernicus GmbH.
Abstract: The TROpospheric WAter RAdiometer (TROWARA) continuously measures integrated water vapour (IWV) with a time resolution of 6 s at Bern in Switzerland. During summer, we often see that IWV has temporal fluctuations during daytime, while the nighttime data are without fluctuations. The data analysis is focused on the year 2010, where TROWARA has a good data quality without data gaps. We derive the spectrum of the IWV fluctuations in the period range from about 1 to 100 min. The FFT spectrum with a window size of 3 months leads to a serious underestimation of the spectral amplitudes of the fluctuations. Thus, we apply a band pass filtering method to derive the amplitudes as a function of period Tp. The amplitudes are proportional to Tp0:5. Another method is the calculation of the moving standard deviation with time window lengths from about 1 to 100 min. Here, we get similar results to those with the band pass filtering method. At all periods, the IWV fluctuations are strongest during summer, while they are smallest during winter. We derive the diurnal variation of the short-term IWV fluctuations by applying a moving standard deviation with a window length of 10 min. The daily cycle is strongest during the summer season, with standard deviations up to 0.22 mm at about 14:00 CET. The diurnal cycle disappears during wintertime. A similar seasonal behaviour is observed in the diurnal cycle of latent heat flux as provided by the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2 reanalysis) at Bern. Further, the 3 d averages of the latent heat flux and the magnitude of the short-term IWV variability show a strong correlation at Bern in 2010 (r D 0:82 with a 95 % confidence interval from 0.75 to 0.87). Thus, we suggest that the diurnal cycle of short-term IWV fluctuations at Bern is mainly caused by large convective heating during daytime in summer. 2019 Author(s).
BibTeX:
@article{Hocke201912083,
  author = {Hocke, K. and Bernet, L. and Hagen, J. and Murk, A. and Renker, M. and Matzler, C.},
  title = {Diurnal cycle of short-term fluctuations of integrated water vapour above Switzerland},
  journal = {Atmospheric Chemistry and Physics},
  publisher = {Copernicus GmbH},
  year = {2019},
  volume = {19},
  number = {19},
  pages = {12083-12090},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073054689&doi=10.5194%2facp-19-12083-2019&partnerID=40&md5=c5c02eb2b07d337d40f83b2a8c16179a},
  doi = {10.5194/acp-19-12083-2019}
}
Houtz D, Naderpour R, Schwank M and Steffen K (2019), "Snow wetness and density retrieved from L-band satellite radiometer observations over a site in the West Greenland ablation zone", Remote Sensing of Environment. Vol. 235 Elsevier Inc..
Abstract: We demonstrate a novel method to retrieve snow liquid water content and density over a site in the ablation zone of the Western Greenland Ice Sheet from L-band radiometer data measured by the Soil Moisture and Ocean Salinity (SMOS) satellite. Previous demonstrations using ground-based close-range radiometry separately retrieved snow density and snow wetness over frozen and thawed ground. We apply similar techniques over the ice sheet to simultaneously retrieve snow density and wetness at the location of “Swiss Camp” from June 2010 through August 2018 at nearly daily temporal resolution. Achieved results are compared to in-situ air temperature data and to a well-known 19 GHz and 37 GHz passive-microwave melt characterization technique known as the cross-polarized gradient ratio (XPGR). The L-band based snow wetness retrievals often detect the onset of seasonal melt earlier than the XPGR algorithm without the need for empirically tuned thresholds. We also demonstrate the performance of the SMOS based snow wetness retrievals based on error statistics compared with an air temperature melt proxy. By applying temporal averaging to the SMOS based snow density retrievals, we achieve reasonable agreement with in-situ observations from May 2014 and May 2018. The demonstrated retrieval algorithm shows potential as a future SMOS data product for ice-covered regions of the cryosphere. 2019 Elsevier Inc.
BibTeX:
@article{Houtz2019,
  author = {Houtz, D. and Naderpour, R. and Schwank, M. and Steffen, K.},
  title = {Snow wetness and density retrieved from L-band satellite radiometer observations over a site in the West Greenland ablation zone},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2019},
  volume = {235},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074707041&doi=10.1016%2fj.rse.2019.111361&partnerID=40&md5=3ab84441cc88ba218c0b98ac8252600e},
  doi = {10.1016/j.rse.2019.111361}
}
Manconi A, Ziegler M, Blochliger T and Wolter A (2019), "Technical note: optimization of unmanned aerial vehicles flight planning in steep terrains", International Journal of Remote Sensing. Taylor and Francis Ltd..
Abstract: We present an approach to manage Unmanned Aerial Vehicle (UAV) photogrammetric data acquisition in areas with steep slopes, i.e., typical conditions of high mountain environments prone to slope instabilities and potentially to catastrophic failures. Starting from the Mission Planner from Ardupilot, an open access and widely used UAV flight planning software, we have developed a set of Matlab™ routines to take into account available topographic relief of the area under investigation. We validated our approach in the Swiss Alps, in a steep slope area where very high-resolution digital models and orthophotos are necessary to analyze fracture surface geometries in detail and to better understand the exfoliation fracture processes. Our results provide a best-practice solution to generate very high-resolution photogrammetric products and can be applied in different UAV mapping tasks and/or monitoring scenarios. 2019, 2019 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Manconi2019,
  author = {Manconi, A. and Ziegler, M. and Blochliger, T. and Wolter, A.},
  title = {Technical note: optimization of unmanned aerial vehicles flight planning in steep terrains},
  journal = {International Journal of Remote Sensing},
  publisher = {Taylor and Francis Ltd.},
  year = {2019},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061013274&doi=10.1080%2f01431161.2019.1573334&partnerID=40&md5=a7b556f53b31e7bd3c2b3ba7107568ba},
  doi = {10.1080/01431161.2019.1573334}
}
Mendez Dominguez E, Magnard C, Meier E, Small D, Schaepman M and Henke D (2019), "A Back-Projection Tomographic Framework for VHR SAR Image Change Detection", IEEE Transactions on Geoscience and Remote Sensing. Vol. 57(7), pp. 4470-4484. Institute of Electrical and Electronics Engineers Inc..
Abstract: Information on 3-D structure expands the scope of change detection applications, for example, in urban studies, human activity, and forest monitoring. Current change detection methods do not fully consider the specifics of SAR data or the properties of the corresponding image focusing techniques. We propose a three-stage method complementing the properties of 2-D and 3-D very high-resolution (VHR) synthetic aperture radar imagery to improve the performance of 2-D only approaches. The method takes advantage of back-projection tomography to ease translation of the 2-D location of the targets into their corresponding 3-D location and vice versa. Detection of changes caused by objects with a small vertical extent is based on the corresponding backscatter difference, while changes caused by objects with a large vertical extent are detected with both backscatter and height difference information combined in a conditional random field. Using multitemporal images, the kappa coefficient improved by a factor of two in comparison with traditional schemes.
BibTeX:
@article{MendezDominguez20194470,
  author = {Mendez Dominguez, E. and Magnard, C. and Meier, E. and Small, D. and Schaepman, M.E. and Henke, D.},
  title = {A Back-Projection Tomographic Framework for VHR SAR Image Change Detection},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  volume = {57},
  number = {7},
  pages = {4470-4484},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068206460&doi=10.1109%2fTGRS.2019.2891308&partnerID=40&md5=3657140738958ac21e994898c1ddb346},
  doi = {10.1109/TGRS.2019.2891308}
}
Mondini A, Santangelo M, Rocchetti M, Rossetto E, Manconi A and Monserrat O (2019), "Sentinel-1 SAR amplitude imagery for rapid landslide detection", Remote Sensing. Vol. 11(7) MDPI AG.
Abstract: Despite landslides impact the society worldwide every day, landslide information isinhomogeneous and lacking. When landslides occur in remote areas or where the availability ofoptical images is rare due to cloud persistence, they might remain unknown, or unnoticed for longtime, preventing studies and hampering civil protection operations. The unprecedented availabilityof SAR C-band images provided by the Sentinel-1 constellation offers the opportunity to proposenew solutions to detect landslides events. In this work, we perform a systematic assessment ofSentinel-1 SAR C-band images acquired before and after known events. We present the resultsof a pilot study on 32 worldwide cases of rapid landslides entailing different types, sizes, slopeexpositions, as well as pre-existing land cover, triggering factors and climatic regimes. Results showthat in about eighty-four percent of the cases, changes caused by landslides on SAR amplitudesare unambiguous, whereas only in about thirteen percent of the cases there is no evidence. On theother hand, the signal does not allow for a systematic use to produce inventories because only in8 cases, a delineation of the landslide borders (i.e., mapping) can be manually attempted. In a fewcases, cascade multi-hazard (e.g., floods caused by landslides) and evidences of extreme triggeringfactors (e.g., strong earthquakes or very rapid snow melting) were detected. The method promises toincrease the availability of information on landslides at different spatial and temporal scales withbenefits for event magnitude assessment during weather-related emergencies, model tuning, andlandslide forecast model validation, in particular when accurate mapping is not required. 2019 by the authors.
BibTeX:
@article{Mondini2019,
  author = {Mondini, A.C. and Santangelo, M. and Rocchetti, M. and Rossetto, E. and Manconi, A. and Monserrat, O.},
  title = {Sentinel-1 SAR amplitude imagery for rapid landslide detection},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2019},
  volume = {11},
  number = {7},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064014108&doi=10.3390%2frs11070760&partnerID=40&md5=92e95fa29e376ea72bb2c4f5da30d7fe},
  doi = {10.3390/rs11070760}
}
Palmisano D, Satalino G, Balenzano A, Bovenga F, Mattia F, Rinaldi M, Ruggieri S, Skriver H, Davidson M, Cartus O and Wegmüller U (2019), "Sensitivity of Sentinel-1 Interferometric Coherence to Crop Structure and Soil Moisture", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 6219-6222. Institute of Electrical and Electronics Engineers Inc..
Abstract: This paper investigates the sensitivity of Sentinel-1 (S-1) interferometric coherence to crop structure and near surface soil moisture (SSM) content. The study analyzes a data set collected in 2017 over the Apulian Tavoliere agricultural site (Southern Italy). The data set includes: i) in situ data over more than 600 agricultural fields monitored during the 2017 winter and spring growing seasons; ii) time-series of S-1 IW VV and VH backscatter and interferometric coherence; iii) time series of S-1 SSM maps. The temporal behavior of S-1 coherence and VH backscatter has been assessed over the monitored agricultural fields. Initial results indicate a stronger sensitivity of S-1 coherence than VH backscatter to crop geometric structure. In addition, an analysis at site scale, conducted before and after an important rain event, indicates a change of SSM from 0.18 to 0.30 m3/m3 along with a change of S-1 coherence from 0.61 to 0.53.
BibTeX:
@conference{Palmisano20196219,
  author = {Palmisano, D. and Satalino, G. and Balenzano, A. and Bovenga, F. and Mattia, F. and Rinaldi, M. and Ruggieri, S. and Skriver, H. and Davidson, M.W.J. and Cartus, O. and Wegmüller, U.},
  title = {Sensitivity of Sentinel-1 Interferometric Coherence to Crop Structure and Soil Moisture},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {6219-6222},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077674004&doi=10.1109%2fIGARSS.2019.8899164&partnerID=40&md5=5b4a90f4cbeca7e6235fcb68a43eb2b7},
  doi = {10.1109/IGARSS.2019.8899164}
}
Rodriguez-Veiga P, Quegan S, Carreiras J, Persson H, Fransson J, Hoscilo A, Ziotkowski D, Sterenczak K, Lohberger S, Stangel M, Berninger A, Siegert F, Avitabile V, Herold M, Mermoz S, Bouvet A, Le Toan T, Carvalhais N, Santoro M, Cartus O, Rauste Y, Mathieu R, Asner G, Thiel C, Pathe C, Schmullius C, Seifert F, Tansey K and Balzter H (2019), "Forest biomass retrieval approaches from earth observation in different biomes", International Journal of Applied Earth Observation and Geoinformation. Vol. 77, pp. 53-68. Elsevier B.V..
Abstract: The amount and spatial distribution of forest aboveground biomass (AGB) were estimated using a range of regionally developed methods using Earth Observation data for Poland, Sweden and regions in Indonesia (Kalimantan), Mexico (Central Mexico and Yucatan peninsula), and South Africa (Eastern provinces) for the year 2010. These regions are representative of numerous forest biomes and biomass levels globally, from South African woodlands and savannas to the humid tropical forest of Kalimantan. AGB retrieval in each region relied on different sources of reference data, including forest inventory plot data and airborne LiDAR observations, and used a range of retrieval algorithms. This is the widest inter-comparison of regional-to-national AGB maps to date in terms of area, forest types, input datasets, and retrieval methods. The accuracy assessment of all regional maps using independent field data or LiDAR AGB maps resulted in an overall root mean square error (RMSE) ranging from 10 t ha −1 to 55 t ha −1 (37% to 67% relative RMSE), and an overall bias ranging from −1 t ha −1 to +5 t ha −1 at pixel level. The regional maps showed better agreement with field data than previously developed and widely used pan-tropical or northern hemisphere datasets. The comparison of accuracy assessments showed commonalities in error structures despite the variety of methods, input data, and forest biomes. All regional retrievals resulted in overestimation (up to 63 t ha −1 ) in the lower AGB classes, and underestimation (up to 85 t ha −1 ) in the higher AGB classes. Parametric model-based algorithms present advantages due to their low demand on in situ data compared to non-parametric algorithms, but there is a need for datasets and retrieval methods that can overcome the biases at both ends of the AGB range. The outcomes of this study should be considered when developing algorithms to estimate forest biomass at continental to global scale level. 2019 The Authors
BibTeX:
@article{RodriguezVeiga201953,
  author = {Rodriguez-Veiga, P. and Quegan, S. and Carreiras, J. and Persson, H.J. and Fransson, J.E.S. and Hoscilo, A. and Ziotkowski, D. and Sterenczak, K. and Lohberger, S. and Stangel, M. and Berninger, A. and Siegert, F. and Avitabile, V. and Herold, M. and Mermoz, S. and Bouvet, A. and Le Toan, T. and Carvalhais, N. and Santoro, M. and Cartus, O. and Rauste, Y. and Mathieu, R. and Asner, G.P. and Thiel, C. and Pathe, C. and Schmullius, C. and Seifert, F.M. and Tansey, K. and Balzter, H.},
  title = {Forest biomass retrieval approaches from earth observation in different biomes},
  journal = {International Journal of Applied Earth Observation and Geoinformation},
  publisher = {Elsevier B.V.},
  year = {2019},
  volume = {77},
  pages = {53-68},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062857698&doi=10.1016%2fj.jag.2018.12.008&partnerID=40&md5=b1b9f49718f14e2b61617f4c6892a6ae},
  doi = {10.1016/j.jag.2018.12.008}
}
Santoro M, Cartus O, Fransson J and Wegmüller U (2019), "Complementarity of X-, C-, and L-band SAR backscatter observations to retrieve forest stem volume in boreal forest", Remote Sensing. Vol. 11(13) MDPI AG.
Abstract: The simultaneous availability of observations from space by remote sensing platforms operating atmultiple frequencies in themicrowave domain suggests investigating their complementarity in thematic mapping and retrieval of biophysical parameters. In particular, there is an interest to understand whether the wealth of short wavelength Synthetic Aperture Radar (SAR) backscatter observations at X-, C-, and L-band from currently operating spaceborne missions can improve the retrieval of forest stem volume, i.e., above-ground biomass, in the boreal zone with respect to a single frequency band. To this scope, repeated observations from TerraSAR-X, Sentinel-1 and ALOS-2 PALSAR-2 from the test sites of Remningstorp and Krycklan, Sweden, have been analyzed and used to estimate stem volume with a retrieval framework based on theWater Cloud Model. Individual estimates of stem volume were then combined linearly to form single-frequency and multi-frequency estimates. The retrieval was assessed at large 0.5 ha forest inventory plots (Remningstorp) and small 0.03 ha forest inventory plots (Krycklan). The relationship between SAR backscatter and stem volume differed depending on forest structure and environmental conditions, in particular at X- and C-band. The highest retrieval accuracy was obtained at both test sites at L-band. The combination of stem volume estimates from data acquired at two or three frequencies achieved an accuracy that was superior to values obtained at a single frequency. When combining estimates from X-, C-, and L-band data, the relative RMSE for the 0.5 ha inventory plots at Remningstorp was 31.3%. For the 0.03 ha inventory plots at Krycklan, the relative RMSE was above 50%. In a retrieval scenario involving short wavelength SAR backscatter data, these results suggest combining multiple frequencies to ensure the highest possible retrieval accuracy achievable. Retrievals should be undertaken to target spatial scales well above the size of a pixel. 2019 by the authors.
BibTeX:
@article{Santoro2019,
  author = {Santoro, M. and Cartus, O. and Fransson, J.E.S. and Wegmüller, U.},
  title = {Complementarity of X-, C-, and L-band SAR backscatter observations to retrieve forest stem volume in boreal forest},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2019},
  volume = {11},
  number = {13},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068529553&doi=10.3390%2frs11131563&partnerID=40&md5=0d6b9d2ea6c9cf9c99729e98c3ad4952},
  doi = {10.3390/rs11131563}
}
Scapozza C, Ambrosi C, Cannata M and Strozzi T (2019), "Glacial lake outburst flood hazard assessment by satellite Earth observation in the Himalayas (Chomolhari area, Bhutan)", Geographica Helvetica. Vol. 74(1), pp. 125-139. Copernicus GmbH.
Abstract: A case study of glacial lakes outburst flood (GLOF) hazard assessment by satellite Earth observation (EO) and numerical modelling is presented for the supraglacial and ice-contact lakes on Thangothang Chhu glacier, Chomolhari area (Bhutan). Detailed geomorphological mapping, including landslide and rock glacier inventories, as well as surface displacement determination using an interferometric SAR (InSAR) satellite, allowed a GLOF hazard assessment for lake Wa-007 to be performed. Outburst scenario modelling was achieved by combining both empirical and numerical modelling approaches, revealing that only a flood wave can have an impact on the two human settlements located downslope of Wa-007 lake. The worst-case scenario, modelled thanks to r.damflood, allowed the wave-front arrival time, the maximum water depth and the arrival time of maximum water height for the two human settlements to be quantified. A long-term monitoring strategy based entirely on EO data, with an update cycle of 5 years, is proposed to assess the future evolution of the area. Author(s) 2019.
BibTeX:
@article{Scapozza2019125,
  author = {Scapozza, C. and Ambrosi, C. and Cannata, M. and Strozzi, T.},
  title = {Glacial lake outburst flood hazard assessment by satellite Earth observation in the Himalayas (Chomolhari area, Bhutan)},
  journal = {Geographica Helvetica},
  publisher = {Copernicus GmbH},
  year = {2019},
  volume = {74},
  number = {1},
  pages = {125-139},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063632674&doi=10.5194%2fgh-74-125-2019&partnerID=40&md5=409841239be1c9df17c28b4ee1052ed9},
  doi = {10.5194/gh-74-125-2019}
}
Schwank M, Li X, Kerr Y, Naderpour R, Matzler C and Wigneron J-P (2019), "tau-Omega- and Two-Stream Emission Models applied to Close-Range and SMOS Measurements", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 6158-6161. Institute of Electrical and Electronics Engineers Inc..
Abstract: An Emission Models (EM) adequate for a retrieval algorithm requires being simple while still capturing the responses of brightness temperatures T textBp, theta to the retrieval parameters. The objective of this study is to explore the benefits of the multiple-scattering Two-Stream (2S) EM over the "Tau-Omega" (TO) EM to retrieve soil Water Content WC and vegetation optical depth τ from L-band T textBp, theta . For sparse and low-scattering vegetation T textB, EMp, theta simulated with EM = TO and EM = 2S converge, which is not the case for dense and strongly scattering vegetation. WCRC and τRC are retrieved with Retrieval Configurations RC = TO, 2S from T textBp, theta measured: i) from a tower within a deciduous forest, and ii) by the "Soil Moisture and Ocean Salinity" (SMOS) mission. Using 2S EM instead of TO EM resulted in marginally lower WCRC retrievals while τRC retrievals are reduced more considerably. With respect to in-situ WCin-situ, retrievals WC2S derived from tower-based T textBp, theta performed better than forest soil water-content WCTO retrieved via the inversion of the "reference" TO EM. Likewise, SMOS based WC2S retrievals revealed better agreement with ECMWF WC simulations than WCTO achieved with the "reference" RC = TO. In short, our study provides clear evidence that it is meaningful to replace TO EM used for current SMOS and SMAP land retrieval with 2S EM.Further advantages of the 2S EM over the TO EM are outlined in this study.
BibTeX:
@conference{Schwank20196158,
  author = {Schwank, M. and Li, X. and Kerr, Y. and Naderpour, R. and Matzler, C. and Wigneron, J.-P.},
  title = {tau-Omega- and Two-Stream Emission Models applied to Close-Range and SMOS Measurements},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {6158-6161},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074882946&doi=10.1109%2fIGARSS.2019.8898225&partnerID=40&md5=dc8078f0b6d421bb25f3c135280e4afe},
  doi = {10.1109/IGARSS.2019.8898225}
}
Siddique M, Strozzi T, Hajnsek I and Frey O (2019), "A Case Study on the Correction of Atmospheric Phases for SAR Tomography in Mountainous Regions", IEEE Transactions on Geoscience and Remote Sensing. Vol. 57(1), pp. 416-431. Institute of Electrical and Electronics Engineers Inc..
Abstract: Synthetic aperture radar (SAR) tomography with repeat-pass acquisitions generally requires a priori phase calibration of the interferometric data stack by compensating for the atmosphere-induced phase delay variations. These variations act as a disturbance in tomographic focusing. In mountainous regions, the mitigation of these disturbances is particularly challenging due to strong spatial variations of the local atmospheric conditions and propagation paths through the troposphere. In this paper, we assess a data-driven approach to estimate these phase variations under a regression-kriging framework. The vertical stratification of the troposphere is modeled functionally, while the impact of the spatial turbulence is considered in a stochastic sense. The methodology entails an initial persistent scatterer interferometry (PSI) analysis. The atmospheric phases isolated for the persistent scatterers (PS) within the PSI processing are considered as samples of the 3-D distribution of the phase delay variations over the scene. These atmospheric phases are regressed against the spatial coordinates in map geometry at PS locations. In turn, kriging predictions are obtained at each location along the elevation profile, where tomographic focusing is intended. A key point of this approach is that the requisite atmospheric corrections are incorporated within the tomographic focusing model. A case study has been performed on a data stack comprising 32 COSMO-SkyMed stripmap images acquired over the Matter Valley in the Swiss Alps, in the summers of 2008-2013. The results show locally improved deformation sampling with tomographic methods compared to the initial PSI solution, primarily due to the improved phase calibration. In general, this paper underscores the indispensability of height-dependent correction of atmospheric phases for SAR tomography.
BibTeX:
@article{Siddique2019416,
  author = {Siddique, M.A. and Strozzi, T. and Hajnsek, I. and Frey, O.},
  title = {A Case Study on the Correction of Atmospheric Phases for SAR Tomography in Mountainous Regions},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  volume = {57},
  number = {1},
  pages = {416-431},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052649884&doi=10.1109%2fTGRS.2018.2855101&partnerID=40&md5=570852f8fd5c26432f03b270289ab67f},
  doi = {10.1109/TGRS.2018.2855101}
}
Siddique M, Wilgan K, Strozzi T, Geiger A, Hajnsek I and Frey O (2019), "A Comparison of Tropospheric Path Delays Estimated in PSI Processing Against Delays Derived from a GNSS Network in the Swiss Alps", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 342-345. Institute of Electrical and Electronics Engineers Inc..
Abstract: This paper reports the first results of a comparative study of tropospheric delays retrieved by means of PSI processing of an interferometric stack of SAR images against those derived independently from a permanent GNSS network. The stack comprises 33 Cosmo-SkyMed stripmap images acquired in the summers between 2008-13 over the Matter Valley in the Swiss Alps. The long-term objective of the study is to explore whether GNSS-derived delays from existing networks (i.e., not deployed specifically for a test site) in Swiss Alpine regions can aid in tropospheric phase corrections in SAR data, or rather the phase corrections derived within the PSI processing being at a higher spatial resolution might be appropriate to build upon the GNSS products by improving their resolution.
BibTeX:
@conference{Siddique2019342,
  author = {Siddique, M.A. and Wilgan, K. and Strozzi, T. and Geiger, A. and Hajnsek, I. and Frey, O.},
  title = {A Comparison of Tropospheric Path Delays Estimated in PSI Processing Against Delays Derived from a GNSS Network in the Swiss Alps},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {342-345},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077680515&doi=10.1109%2fIGARSS.2019.8899799&partnerID=40&md5=e83f560a210de55db0f4920774cfed6c},
  doi = {10.1109/IGARSS.2019.8899799}
}
Wiesmann A, Caduff R, Werner C, Frey O, Schneebeli M, Lowe H, Jaggi M, Schwank M, Naderpour R and Fehr T (2019), "ESA SnowLab Project: 4 Years of Wide Band Scatterometer Measurements of Seasonal Snow", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 5745-5748. Institute of Electrical and Electronics Engineers Inc..
Abstract: The aim of the ESA SnowLab project is to provide a comprehensive multi-frequency, multi-polarisation, multi-temporal dataset of active microwave measurements over snow-covered grounds to investigate the relationship between effective snow- and ground parameters and the resultant signals detected by microwave radar. An important part for the development of microwave models is the microstructural characterisation. This characterisation can only be done by repeated measurements by SnowMicroPen and more completely, but also much more expensive, by X-ray micro-tomography. Within this project we complemented the microwave measurements of Alpine snow in Switzerland with extensive effective snow- and ground parameters and meteorological data. Microwave backscatter measurements were conducted using the 9 - 18 GHz ESA SnowScat instrument and since December 2018 the recently built ESA WBScat instrument. WBScat allows to extend the spectral coverage to 1 - 40 GHz.
BibTeX:
@conference{Wiesmann20195745,
  author = {Wiesmann, A. and Caduff, R. and Werner, C. and Frey, O. and Schneebeli, M. and Lowe, H. and Jaggi, M. and Schwank, M. and Naderpour, R. and Fehr, T.},
  title = {ESA SnowLab Project: 4 Years of Wide Band Scatterometer Measurements of Seasonal Snow},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2019},
  pages = {5745-5748},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077691980&doi=10.1109%2fIGARSS.2019.8898961&partnerID=40&md5=8bd7f90b83c18a1c0ad6e29f0165a302},
  doi = {10.1109/IGARSS.2019.8898961}
}
Wilgan K, Siddique M, Strozzi T, Geiger A and Frey O (2019), "Comparison of tropospheric path delay estimates from GNSS and space-borne SAR interferometry in alpine conditions", Remote Sensing. Vol. 11(15) MDPI AG.
Abstract: We compare tropospheric delays from Global Navigation Satellite Systems (GNSS) and Synthetic Aperture Radar (SAR) Interferometry (InSAR) in a challenging mountainous environment in the Swiss Alps, where strong spatial variations of the local tropospheric conditions are often observed. Tropospheric delays are usually considered to be an error for both GNSS and InSAR, and are typically removed. However, recently these delays are also recognized as a signal of interest, for example for assimilation into numerical weather models or climate studies. The GNSS and InSAR are techniques of complementary nature, as one has sparse spatial but high temporal resolution, and the other very dense spatial coverage but repeat pass of only a few days. This raises expectations for a combination of these techniques. For this purpose, a comprehensive comparison between the techniques must be first performed. Due to the relative nature of InSAR estimates, we compare the difference slant tropospheric delays (dSTD) retrieved from GNSS with the dSTDs estimated using Persistent Scatterer Interferometry (PSI) of 32 COSMO-SkyMed SAR images taken in a snow-free period from June to October between 2008 and 2013. The GNSS estimates calculated at permanent geodetic stations are interpolated to the locations of persistent scatterers using an in-house developed least-squares collocation software COMEDIE. The Pearson's correlation coefficient between InSAR and GNSS estimates averaged over all acquisitions is equal to 0.64 and larger than 0.8 for approximately half of the layers. Better agreement is obtained mainly for days with high variability of the troposphere (relative to the tropospheric conditions at the time of the reference acquisition), expressed as standard deviations of the GNSS-based dSTDs. On the other hand, the most common feature for the days with poor agreement is represented by very stable, almost constant GNSS estimates. In addition, there is a weak correlation between the agreement and the water vapor values in the area, as well as with the number of stations in the closest vicinity of the study area. Adding low-cost L-1 only GPS stations located within the area of the study increases the biases for most of the dates, but the standard deviations between InSAR and GNSS decrease for the limited area with low-cost stations. 2019 by the authors.
BibTeX:
@article{Wilgan2019,
  author = {Wilgan, K. and Siddique, M.A. and Strozzi, T. and Geiger, A. and Frey, O.},
  title = {Comparison of tropospheric path delay estimates from GNSS and space-borne SAR interferometry in alpine conditions},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2019},
  volume = {11},
  number = {15},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070463337&doi=10.3390%2frs11151789&partnerID=40&md5=db4909ae89cd746b6462fdf77de009d2},
  doi = {10.3390/rs11151789}
}
Zheng D, Li X, Wang X, Wang Z, Wen J, van der Velde R, Schwank M and Su Z (2019), "Sampling depth of L-band radiometer measurements of soil moisture and freeze-thaw dynamics on the Tibetan Plateau", Remote Sensing of Environment. Vol. 226, pp. 16-25. Elsevier Inc..
Abstract: Knowing the exact sampling depth of microwave radiometry is essential for quantifying the performance and appreciation of the applicability of satellite soil moisture products. We investigate in this study the sampling depth (δ SM ) of the L-band microwave emission under frozen and thawed soil conditions on the Tibetan Plateau. Two years of diurnal brightness temperature (T B p ) measurements at a time interval of 30 min are collected by the ELBARA-III radiometer deployed at a Tibetan meadow site. Vertical profiles of soil temperature and volumetric liquid water content (θ liq ) are measured simultaneously at soil depths up to 1 m below the surface. The impact of the θ liq measured at different depths on the microwave emission simulations is assessed using the τ-ω emission model, whereby the permittivity of frozen and thawed soil is estimated by the four-phase dielectric mixing model. It is found that: 1) the sampling depth for the effective temperature depends on the magnitude of θ liq , and is estimated to be, on average, about 50 and 15 cm for the cold dry and wet warm period, respectively, because of the seasonality in θ liq ; 2) the δ SM is determined at 2.5 cm for both frozen and thawed soil conditions during both cold and warm periods, which is shallower than the commonly used θ liq measurement depth (i.e. 5 cm) adopted for the in-situ monitoring networks across the globe; 3) the T B p simulations performed with the θ liq measurements taken at the estimated δ SM of 2.5 cm result in lower unbiased root mean squared errors, about 14% (3.16 K) and 22% (3.36 K) for the horizontal and vertical polarizations respectively, in comparison to the simulations with the θ liq measurements taken from 5 cm soil depth; and 4) the θ liq retrieved with the single channel algorithm from the ELBARA-III measured vertically polarized T B p are in better agreement with the θ liq measured at 2.5 cm than the one measured at 5 cm. These findings are crucial for developing strategies for the calibration/validation as well as the application of satellite based soil moisture products relying on the L-band radiometry. 2019 Elsevier Inc.
BibTeX:
@article{Zheng201916,
  author = {Zheng, D. and Li, X. and Wang, X. and Wang, Z. and Wen, J. and van der Velde, R. and Schwank, M. and Su, Z.},
  title = {Sampling depth of L-band radiometer measurements of soil moisture and freeze-thaw dynamics on the Tibetan Plateau},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2019},
  volume = {226},
  pages = {16-25},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063607073&doi=10.1016%2fj.rse.2019.03.029&partnerID=40&md5=99af5b33a448880ee3bca830b799c408},
  doi = {10.1016/j.rse.2019.03.029}
}
Ambrosi C, Strozzi T, Scapozza C and Wegmüller U (2018), "Landslide hazard assessment in the Himalayas (Nepal and Bhutan) based on Earth-Observation data", Engineering Geology. Vol. 237, pp. 217-228. Elsevier B.V..
Abstract: The Himalayan range is a high-risk area where landslides can destroy villages, access roads, and other important infrastructures and cause numerous injuries and deaths each year. Hazard assessment is one of the most important actions in the disaster risk management strategy with a direct impact on land use and land planning. Because of a lack of diffuse field data and mapping, landslide hazard maps are however not available for vast regions of the Himalayas. Earth-Observation (EO) data can support the preparation of landslide hazard maps through the compilation of landslide inventory maps at regional scale by means of satellite photo-interpretation and the assessment of the state of activity of mapped phenomena based on surface displacement rates quantified from satellite SAR interferometry. We compiled landslide inventory maps and landslide hazard maps for two areas in Nepal and Bhutan. For the Lukla region in Nepal, our analysis indicates that 10.5% of the total area of 725 km2 is affected by landslides and 57% of the mapped landslides are classified as active. For the Chomolhari area in Bhutan, 6% of the total area of 620 km2 is affected by landslides and 55% of them are classified as active. For both regions rockslides represent the most mapped phenomena. Landslide hazard assessment over large regions based on EO products represents an important aspect for disaster risk reduction not only in the whole Himalayan region but also in other mountain areas worldwide in absence of detailed landslide inventory maps. 2018 Elsevier B.V.
BibTeX:
@article{Ambrosi2018217,
  author = {Ambrosi, C. and Strozzi, T. and Scapozza, C. and Wegmüller, U.},
  title = {Landslide hazard assessment in the Himalayas (Nepal and Bhutan) based on Earth-Observation data},
  journal = {Engineering Geology},
  publisher = {Elsevier B.V.},
  year = {2018},
  volume = {237},
  pages = {217-228},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043375715&doi=10.1016%2fj.enggeo.2018.02.020&partnerID=40&md5=c6a98e3aebeebd09077e436ff7f352c7},
  doi = {10.1016/j.enggeo.2018.02.020}
}
Antonova S, Sudhaus H, Strozzi T, Zwieback S, Kaab A, Heim B, Langer M, Bornemann N and Boike J (2018), "Thaw subsidence of a yedoma landscape in Northern Siberia, measured in situ and estimated from TerraSAR-X Interferometry", Remote Sensing. Vol. 10(4) MDPI AG.
Abstract: In permafrost areas, seasonal freeze-thaw cycles result in upward and downward movements of the ground. For some permafrost areas, long-term downward movements were reported during the last decade. We measured seasonal and multi-year ground movements in a yedoma region of the Lena River Delta, Siberia, in 2013-2017, using reference rods installed deep in the permafrost. The seasonal subsidence was 1.7 ± 1.5 cm in the cold summer of 2013 and 4.8 ± 2 cm in the warm summer of 2014. Furthermore, we measured a pronounced multi-year net subsidence of 9.3 ± 5.7 cm from spring 2013 to the end of summer 2017. Importantly, we observed a high spatial variability of subsidence of up to 6 cm across a sub-meter horizontal scale. In summer 2013, we accompanied our field measurements with Differential Synthetic Aperture Radar Interferometry (DInSAR) on repeat-pass TerraSAR-X (TSX) data from the summer of 2013 to detect summer thaw subsidence over the same study area. Interferometry was strongly affected by a fast phase coherence loss, atmospheric artifacts, and possibly the choice of reference point. A cumulative ground movement map, built from a continuous interferogram stack, did not reveal a subsidence on the upland but showed a distinct subsidence of up to 2 cm in most of the thermokarst basins. There, the spatial pattern of DInSAR-measured subsidence corresponded well with relative surface wetness identified with the near infra-red band of a high-resolution optical image. Our study suggests that (i) although X-band SAR has serious limitations for ground movement monitoring in permafrost landscapes, it can provide valuable information for specific environments like thermokarst basins, and (ii) due to the high sub-pixel spatial variability of ground movements, a validation scheme needs to be developed and implemented for future DInSAR studies in permafrost environments. 2018 by the authors.
BibTeX:
@article{Antonova2018,
  author = {Antonova, S. and Sudhaus, H. and Strozzi, T. and Zwieback, S. and Kaab, A. and Heim, B. and Langer, M. and Bornemann, N. and Boike, J.},
  title = {Thaw subsidence of a yedoma landscape in Northern Siberia, measured in situ and estimated from TerraSAR-X Interferometry},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045981435&doi=10.3390%2frs10040494&partnerID=40&md5=763d32f1c3b4a6d0ea01436392e9ee19},
  doi = {10.3390/rs10040494}
}
Baffelli S, Frey O and Hajnsek I (2018), "Geostatistical analysis and mitigation of atmosphere induced phase in terrestrial radar interferometric observations of an alpine glacier", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2018-June, pp. 626-631. Institute of Electrical and Electronics Engineers Inc..
Abstract: Terrestrial Radar Interferometry is used to map surface displacement velocites with high temporal resolution, irrespective of sunlight and cloud cover. The main factor limiting estimation accuracy are variations in the atmospheric refractive index, observed as atmospheric phase screens (APS). A statistical model for APS assuming a separable spatio-temporal covariance structure is described. It facilitates the extrapolation of the APS from observations at persistent scatterers (PS) using regression-Kriging, which is followed by a timeseries inversion to estimate the surface velocity. A statistical analysis of the APS is performed using a Ku-Band radar timeseries of Bisgletscher, a glacier in the Southwestern Swiss Alps. The results show that, while some non-stationarity in the covariance structure is observed at large timescales, the covariance models obtained assuming separability perform well in APS mitigation using regression-Kriging. VDE VERLAG GMBH  Berlin  Offenbach.
BibTeX:
@conference{Baffelli2018626,
  author = {Baffelli, S. and Frey, O. and Hajnsek, I.},
  title = {Geostatistical analysis and mitigation of atmosphere induced phase in terrestrial radar interferometric observations of an alpine glacier},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-June},
  pages = {626-631},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050470984&partnerID=40&md5=b37be343722601d990414b037f4fe628}
}
Baffelli S, Frey O and Hajnsek I (2018), "Geostatistical analysis and mitigation of atmospheric phase screens in Ku-band terrestrial radar interferometry", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6504-6507. Institute of Electrical and Electronics Engineers Inc..
Abstract: A geostatistical analysis of the atmospheric phase screen (APS) affecting Ku-Band terrestrial radar interferometric (TRI) observations of a fast-flowing alpine glacier is made assuming a separable spatio-temporal covariance structure. Such a structure facilitates the mitigation of APS: the atmospheric phase affecting individual interferograms can be extrapolated form a set of persistent scatterers (PS) using regression-Kriging. After removing this estimate the residual APS is only correlated in time; its effect on surface displacement estimation is mitigated with a generalized least squares (GLS) inversion employing an estimate of the temporal covariance of the APS. The applicability of a separable covariance structure and the performance of the APS correction method are assessed on a TRI timeseries of Bisgletscher, a glacier in the southwestern Swiss Alps. 2018 IEEE
BibTeX:
@conference{Baffelli20186504,
  author = {Baffelli, S. and Frey, O. and Hajnsek, I.},
  title = {Geostatistical analysis and mitigation of atmospheric phase screens in Ku-band terrestrial radar interferometry},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6504-6507},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063126277&doi=10.1109%2fIGARSS.2018.8517479&partnerID=40&md5=b9a16841fd01f94a78dc79f7ae59b11b},
  doi = {10.1109/IGARSS.2018.8517479}
}
Baffelli S, Frey O, Werner C and Hajnsek I (2018), "Polarimetric calibration of the ku-band advanced polarimetric radar interferometer", IEEE Transactions on Geoscience and Remote Sensing. Vol. 56(4), pp. 2295-2311. Institute of Electrical and Electronics Engineers Inc..
Abstract: Differential interferometry using ground-based radar systems permits to monitor displacements in natural terrain with high flexibility in location, time of acquisition, and revisit time. In combination with polarimetric imaging, discrimination of different scattering mechanisms present in a resolution cell can be obtained simultaneously with the estimation of surface displacement. In this paper, we present the preprocessing steps and the calibration procedure required to produce high-quality calibrated polarimetric single-look complex imagery with KAPRI, a new portable Ku-band polarimetric radar interferometer. The processing of KAPRI data into single look complex images is addressed, including the correction of beam squint and of azimuthal phase variations. A polarimetric calibration model adapted to the acquisition mode is presented and used to produce calibrated polarimetric covariance matrix data. The methods are validated by means of a scene containing five trihedral corner reflectors. Data preprocessing is assessed by analyzing the oversampled response of a corner reflector, and the polarimetric calibration quality is verified by computing polarimetric signatures and residual calibration parameters.
BibTeX:
@article{Baffelli20182295,
  author = {Baffelli, S. and Frey, O. and Werner, C. and Hajnsek, I.},
  title = {Polarimetric calibration of the ku-band advanced polarimetric radar interferometer},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {56},
  number = {4},
  pages = {2295-2311},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85039768815&doi=10.1109%2fTGRS.2017.2778049&partnerID=40&md5=6751425ed59d75041166ea7aeb997f4f},
  doi = {10.1109/TGRS.2017.2778049}
}
Balenzano A, Satalino G, Lovergine F, Mattia F, Cartus O, Davidson M, Al-Khaldi M and Johnson J (2018), "Cross-comparison of three SAR soil moisture retrieval algorithms using synthetic and experimental data", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6123-6126. Institute of Electrical and Electronics Engineers Inc..
Abstract: The objective of this study is to cross-compare three algorithms for retrieving surface soil moisture (SSM) from ESA's Sentinel-1 (S-1) data. The context is provided by the large scientific and application interest in SSM products at high resolution and regional/continental scale that can be retrieved from S-1 data alone or in combination with other missions such as NASA/SMAP and ESA/SMOS. Of the three investigated algorithms, one inverts a scattering model exploiting a Bayesian approach, whereas the other two are change detection approaches. The cross-comparison is carried out by using both simulated and experimental data. Strengths and weaknesses of the three algorithms are identified and discussed. 2018 IEEE
BibTeX:
@conference{Balenzano20186123,
  author = {Balenzano, A. and Satalino, G. and Lovergine, F. and Mattia, F. and Cartus, O. and Davidson, M. and Al-Khaldi, M. and Johnson, J.},
  title = {Cross-comparison of three SAR soil moisture retrieval algorithms using synthetic and experimental data},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6123-6126},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063139800&doi=10.1109%2fIGARSS.2018.8517759&partnerID=40&md5=7dbdda81d48da320e6f67ad0b6164089},
  doi = {10.1109/IGARSS.2018.8517759}
}
Bickel V, Manconi A and Amann F (2018), "Quantitative assessment of digital image correlation methods to detect and monitor surface displacements of large slope instabilities", Remote Sensing. Vol. 10(6) MDPI AG.
Abstract: We evaluate the capability of three different digital image correlation (DIC) algorithms to measure long-term surface displacement caused by a large slope instability in the Swiss Alps. DIC was applied to high-resolution optical imagery taken by airborne sensors, and the accuracy of the displacements assessed against global navigation satellite system measurements. A dynamic radiometric correction of the input images prior to DIC application was shown to enhance both the correlation success and accuracy. Moreover, a newly developed spatial filter considering the displacement direction and magnitude proved to be an effective tool to enhance DIC performance and accuracy. Our results show that all algorithms are capable of quantifying slope instability displacements, with average errors ranging from 8 to 12% of the observed maximum displacement, depending on the DIC processing parameters, and the pre- and postprocessing of the in- and output. Among the tested approaches, the results based on a fast Fourier transform correlation approach provide a considerably better spatial coverage of the displacement field of the slope instability. The findings of this study are relevant for slope instability detection and monitoring via DIC, especially in the context of an ever-increasing availability of high-resolution air- and spaceborne imagery. 2018 by the authors.
BibTeX:
@article{Bickel2018,
  author = {Bickel, V.T. and Manconi, A. and Amann, F.},
  title = {Quantitative assessment of digital image correlation methods to detect and monitor surface displacements of large slope instabilities},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {6},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048984521&doi=10.3390%2frs10060865&partnerID=40&md5=2ebcb7c63822a1d7a134b979b68f9ba0},
  doi = {10.3390/rs10060865}
}
Boncori J, Andersen M, Dall J, Kusk A, Kamstra M, Andersen S, Bechor N, Bevan S, Bignami C, Gourmelen N, Joughin I, Jung H-S, Luckman A, Mouginot J, Neelmeijer J, Rignot E, Scharrer K, Nagler T, Scheuchl B and Strozzi T (2018), "Intercomparison and validation of SAR-based ice velocity measurement techniques within the Greenland Ice Sheet CCI project", Remote Sensing. Vol. 10(6) MDPI AG.
Abstract: Ice velocity is one of the products associated with the Ice Sheets Essential Climate Variable. This paper describes the intercomparison and validation of ice-velocity measurements carried out by several international research groups within the European Space Agency Greenland Ice Sheet Climate Change Initiative project, based on space-borne Synthetic Aperture Radar (SAR) data. The goal of this activity was to survey the best SAR-based measurement and error characterization approaches currently in practice. To this end, four experiments were carried out, related to different processing techniques and scenarios, namely differential SAR interferometry, multi aperture SAR interferometry and offset-tracking of incoherent as well as of partially-coherent data. For each task, participants were provided with common datasets covering areas located on the Greenland ice-sheet margin and asked to provide mean velocity maps, quality characterization and a description of processing algorithms and parameters. The results were then intercompared and validated against GPS data, revealing in several cases significant differences in terms of coverage and accuracy. The algorithmic steps and parameters influencing the coverage, accuracy and spatial resolution of the measurements are discussed in detail for each technique, as well as the consistency between quality parameters and validation results. This allows several recommendations to be formulated, in particular concerning procedures which can reduce the impact of analyst decisions, and which are often found to be the cause of sub-optimal algorithm performance. 2018 by the authors.
BibTeX:
@article{Boncori2018,
  author = {Boncori, J.P.M. and Andersen, M.L. and Dall, J. and Kusk, A. and Kamstra, M. and Andersen, S.B. and Bechor, N. and Bevan, S. and Bignami, C. and Gourmelen, N. and Joughin, I. and Jung, H.-S. and Luckman, A. and Mouginot, J. and Neelmeijer, J. and Rignot, E. and Scharrer, K. and Nagler, T. and Scheuchl, B. and Strozzi, T.},
  title = {Intercomparison and validation of SAR-based ice velocity measurement techniques within the Greenland Ice Sheet CCI project},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {6},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048953457&doi=10.3390%2frs10060929&partnerID=40&md5=f08a7168334b41a3c4400863b5163cc1},
  doi = {10.3390/rs10060929}
}
Cartus O, Siqueira P and Kellndorfer J (2018), "An error model for mapping forest cover and forest cover change using L-band SAR", IEEE Geoscience and Remote Sensing Letters. Vol. 15(1), pp. 107-111. Institute of Electrical and Electronics Engineers Inc..
Abstract: We present an error model for forest cover mapping and change detection with L-band synthetic aperture radar (SAR), which considers measurement noise, forest height, number of images available, and imaging conditions. When applied to a multiseasonal set of Advanced Land Observing Satellite Phased-Array type L-band SAR images acquired over a forest site in southern Sweden, the error model, which is founded on a semiempirical model, suggests that a bitemporal set of crosspolarized L-band backscatter observations is sufficient to detect a forest cover loss of 50% at hectare scale for mature forests. The error probability increases when using co-polarization images, images acquired under adverse imaging conditions, or when detecting forest cover change in a forest of low height. The availability of multitemporal L-band observations is expected to improve forest cover retrieval and change detection, albeit highly correlated forest cover retrieval errors between images acquired within narrow time intervals (e.g., months) pose a limit on the improvements that can be achieved.
BibTeX:
@article{Cartus2018107,
  author = {Cartus, O. and Siqueira, P. and Kellndorfer, J.},
  title = {An error model for mapping forest cover and forest cover change using L-band SAR},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {15},
  number = {1},
  pages = {107-111},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038823609&doi=10.1109%2fLGRS.2017.2775659&partnerID=40&md5=f55dc1ec0e52d0ea4f27150d39c42649},
  doi = {10.1109/LGRS.2017.2775659}
}
Coscione R, Hajnsek I and Frey O (2018), "An experimental car-borne SAR system: Measurement setup and positioning error analysis", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6364-6367. Institute of Electrical and Electronics Engineers Inc..
Abstract: Repeat-pass differential SAR interferometry (DInSAR) using spaceborne SAR data or stationary terrestrial radar data is an established technique to measure surface displacements. However, repeat-pass DInSAR from agile platforms (airborne/car-borne) is challenging due to residual motion errors. This is particularly true for high-frequency radar where motion errors of few millimeters represent a non-negligible fraction of the wavelength. In this paper, an experimental car-borne SAR system is presented. Such a system is complementary to the existing solutions (namely spaceborne, airborne, and terrestrial systems) in terms of geometry of acquisition, and flexibility in the selection of temporal baselines and location of the acquisitions. To meet the need of consistent and precise trajectory information, proper postprocessing procedure must be applied to the raw positioning data collected from the inertial navigation system (INS) and the global positioning system (GNSS). A viable procedure is here presented and first results discussed.
BibTeX:
@conference{Coscione20186364,
  author = {Coscione, R. and Hajnsek, I. and Frey, O.},
  title = {An experimental car-borne SAR system: Measurement setup and positioning error analysis},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6364-6367},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064274232&doi=10.1109%2fIGARSS.2018.8519408&partnerID=40&md5=ef1ff23b08eee2224650c498e3d86bbf},
  doi = {10.1109/IGARSS.2018.8519408}
}
Da Lio C, Teatini P, Strozzi T and Tosi L (2018), "Understanding land subsidence in salt marshes of the Venice Lagoon from SAR Interferometry and ground-based investigations", Remote Sensing of Environment. Vol. 205, pp. 56-70. Elsevier Inc..
Abstract: The existence of salt marshes and tidal morphologies is strictly connected to their elevation with respect to the mean sea level. Quantifying land subsidence of these high-valued transitional environments is therefore crucial to investigate their long-term possible survival, also in view of the expected climate changes. However, monitoring with a certain accuracy their movements has been challenging until now due to the peculiar features of these morphological forms: they are difficult to access, made of largely unconsolidated deposits, without anthropogenic structures, relatively far from anthropogenic facilities, and become submerged by the sea water twice a day. For these reasons, they have never be linked to traditional levelling and GPS networks, and also standard Interferometric SAR applications returned very poor results in terms of spatial and temporal coverage. An advanced Persistent Scatterer Interferometry (PSI) technique on a 5-year long stack of X-bandwidth SAR acquisitions of the Venice Lagoon is here presented. The regularity of the acquisitions, the short satellite revisiting time (11 days), the high image resolution (  3 × 3 m), and the strategies used in the PSI application have allowed us to detect thousands of measurable persistent targets (PTs) in the Venice Lagoon salt marshes. The measured displacements range from small uplifts to subsidence rates of more than 20 mm/yr. The analyses of the observed displacements point out that land subsidence is much larger on man-made than natural salt marshes, with a significant negative correlation with the marsh age. In addition, land subsidence with the presence of halophytic vegetation species is generally smaller than on unvegetated marshes. Finally, at a few selected sites, the integration of the PSI outcome with local ground-based measurements, such as multi-depth benchmarks, feldspar marker horizons and surface elevation tables, has allowed quantifying the displacement variability versus depth and therefore developing a first conceptual model of the salt marsh consolidation and accretion processes. 2017 Elsevier Inc.
BibTeX:
@article{DaLio201856,
  author = {Da Lio, C. and Teatini, P. and Strozzi, T. and Tosi, L.},
  title = {Understanding land subsidence in salt marshes of the Venice Lagoon from SAR Interferometry and ground-based investigations},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2018},
  volume = {205},
  pages = {56-70},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034809299&doi=10.1016%2fj.rse.2017.11.016&partnerID=40&md5=4371863f1b54d1ad2d2bb8fd3a640c6e},
  doi = {10.1016/j.rse.2017.11.016}
}
Frey O, Werner C, Caduff R and Wiesmann A (2018), "Tomographic profiling with SnowScat within the ESA SnowLab campaign: Time series of snow profiles over three snow seasons", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6512-6515. Institute of Electrical and Electronics Engineers Inc..
Abstract: As part of the ESA SnowLab campaign the SnowScat device, a terrestrial stepped-frequency continuous-wave (SFCW) scatterometer which supports fully-polarimetric measurements within a frequency band from 9.2 to 17.8 GHz, was operated in tomographic profiling mode. In this tomographic profiling mode the SnowScat device is subsequently displaced in elevation direction to obtain a high-resolution not only in range direction but also along elevation. This leads to two-dimensional vertical profiles of a snowpack, which means that radar backscatter, co-polar phase difference, interferometric phase and coherence can be distinguished also along the vertical dimension of the snowpack. In this paper, we provide a summary and a few examples of a time series of tomographic measurements of snow obtained within the ESA SnowLab campaign at two different locations in the Swiss Alps during three snow seasons. 2018 IEEE
BibTeX:
@conference{Frey20186512,
  author = {Frey, O. and Werner, C.L. and Caduff, R. and Wiesmann, A.},
  title = {Tomographic profiling with SnowScat within the ESA SnowLab campaign: Time series of snow profiles over three snow seasons},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6512-6515},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063131128&doi=10.1109%2fIGARSS.2018.8517692&partnerID=40&md5=7545c974d34eafeaca6b498d4a336df7},
  doi = {10.1109/IGARSS.2018.8517692}
}
Frey O, Werner C, Hajnsek I and Coscione R (2018), "A car-borne SAR system for interferometric measurements: Development status and system enhancements", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6508-6511. Institute of Electrical and Electronics Engineers Inc..
Abstract: Terrestrial radar systems are used operationally for area-wide measurement and monitoring of surface displacements on steep slopes, as prevalent in mountainous areas or also in open pit mines. One limitation of these terrestrial systems is the decreasing cross-range resolution with increasing distance of observation due to the limited antenna size of the real aperture radar or the limited synthetic aperture of the quasi-stationary SAR systems. Recently, we have conducted a first experiment using a car-borne SAR system at Ku-band, demonstrating the time-domain back-projection (TDBP) focusing capability for the FMCW case and single-pass interferometric capability of our experimental Ku-band car-borne SAR system. The cross-range spatial resolution provided by such a car-based SAR system is potentially independent from the distance of observation, given that an adequate sensor trajectory can be built. In this paper, we give (1) an overview of the updated system hardware (radar setup and high-precision combined INS/GNSS positioning and attitude determination), and (2) present SAR imagery obtained with the updated prototype Ku-band car-borne SAR system. 2018 IEEE
BibTeX:
@conference{Frey20186508,
  author = {Frey, O. and Werner, C.L. and Hajnsek, I. and Coscione, R.},
  title = {A car-borne SAR system for interferometric measurements: Development status and system enhancements},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6508-6511},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064167926&doi=10.1109%2fIGARSS.2018.8518840&partnerID=40&md5=7d402ef47562ff6c2557ee137b61e1fe},
  doi = {10.1109/IGARSS.2018.8518840}
}
Grigoli F, Cesca S, Rinaldi A, Manconi A, Lopez-Comino J, Clinton J, Westaway R, Cauzzi C, Dahm T and Wiemer S (2018), "The November 2017 Mw5.5 Pohang earthquake: A possible case of induced seismicity in South Korea", Science. Vol. 360(6392), pp. 1003-1006. American Association for the Advancement of Science.
Abstract: The moment magnitude (Mw) 5.5 earthquake that struck South Korea in November 2017 was one of the largest and most damaging events in that country over the past century. Its proximity to an enhanced geothermal system site, where high-pressure hydraulic injection had been performed during the previous 2 years, raises the possibility that this earthquake was anthropogenic. We have combined seismological and geodetic analyses to characterize the mainshock and its largest aftershocks, constrain the geometry of this seismic sequence, and shed light on its causal factors. According to our analysis, it seems plausible that the occurrence of this earthquake was influenced by the aforementioned industrial activities. Finally, we found that the earthquake transferred static stress to larger nearby faults, potentially increasing the seismic hazard in the area. 2017 The Authors.
BibTeX:
@article{Grigoli20181003,
  author = {Grigoli, F. and Cesca, S. and Rinaldi, A.P. and Manconi, A. and Lopez-Comino, J.A. and Clinton, J.F. and Westaway, R. and Cauzzi, C. and Dahm, T. and Wiemer, S.},
  title = {The November 2017 Mw5.5 Pohang earthquake: A possible case of induced seismicity in South Korea},
  journal = {Science},
  publisher = {American Association for the Advancement of Science},
  year = {2018},
  volume = {360},
  number = {6392},
  pages = {1003-1006},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046696950&doi=10.1126%2fscience.aat2010&partnerID=40&md5=5104f2d315278c2872f550b3c3adbe14},
  doi = {10.1126/science.aat2010}
}
Lemmetyinen J, Derksen C, Rott H, Macelloni G, King J, Schneebeli M, Wiesmann A, Leppanen L, Kontu A and Pulliainen J (2018), "Retrieval of effective correlation length and snow water equivalent from radar and passive microwave measurements", Remote Sensing. Vol. 10(2) MDPI AG.
Abstract: Current methods for retrieving SWE (snow water equivalent) from space rely on passive microwave sensors. Observations are limited by poor spatial resolution, ambiguities related to separation of snow microstructural properties from the total snow mass, and signal saturation when snow is deep (  > 80 cm). The use of SAR (Synthetic Aperture Radar) at suitable frequencies has been suggested as a potential observation method to overcome the coarse resolution of passive microwave sensors. Nevertheless, suitable sensors operating from space are, up to now, unavailable. Active microwave retrievals suffer, however, from the same difficulties as the passive case in separating impacts of scattering efficiency from those of snow mass. In this study, we explore the potential of applying active (radar) and passive (radiometer) microwave observations in tandem, by using a dataset of co-incident tower-based active and passive microwave observations and detailed in situ data from a test site in Northern Finland. The dataset spans four winter seasons with daily coverage. In order to quantify the temporal variability of snow microstructure, we derive an effective correlation length for the snowpack (treated as a single layer), which matches the simulated microwave response of a semi-empirical radiative transfer model to observations. This effective parameter is derived from radiometer and radar observations at different frequencies and frequency combinations (10.2, 13.3 and 16.7 GHz for radar; 10.65, 18.7 and 37 GHz for radiometer). Under dry snow conditions, correlations are found between the effective correlation length retrieved from active and passive measurements. Consequently, the derived effective correlation length from passive microwave observations is applied to parameterize the retrieval of SWE using radar, improving retrieval skill compared to a case with no prior knowledge of snow-scattering efficiency. The same concept can be applied to future radar satellite mission concepts focused on retrieving SWE, exploiting existing methods for retrieval of snow microstructural parameters, as employed within the ESA (European Space Agency) GlobSnow SWE product. Using radar alone, a seasonally optimized value of effective correlation length to parameterize retrievals of SWE was sufficient to provide an accuracy of < 25 mm (unbiased) Root-Mean Square Error using certain frequency combinations. A temporally dynamic value, derived from e.g., physical snow models, is necessary to further improve retrieval skill, in particular for snow regimes with larger temporal variability in snow microstructure and a more pronounced layered structure. 2018 by the authors.
BibTeX:
@article{Lemmetyinen2018,
  author = {Lemmetyinen, J. and Derksen, C. and Rott, H. and Macelloni, G. and King, J. and Schneebeli, M. and Wiesmann, A. and Leppanen, L. and Kontu, A. and Pulliainen, J.},
  title = {Retrieval of effective correlation length and snow water equivalent from radar and passive microwave measurements},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {2},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042531312&doi=10.3390%2frs10020170&partnerID=40&md5=5b09d59e61d25e8d9f8462fee48520ef},
  doi = {10.3390/rs10020170}
}
Magnard C, Wegmüller U, Werner C, Bonvin F and Meier E (2018), "Planning tool for SAR missions", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2018-June, pp. 1052-1057. Institute of Electrical and Electronics Engineers Inc..
Abstract: A methodology was developed to assist in the planning of SAR acquisitions, supported by a user-friendly software. Using sensor parameters, the position and topography of the region of interest, and a proposed flight path, this planning tool simulates backscatter images, maps of scattering characteristics and image quality parameters such as the local incidence angle and the noise equivalent sigmaO. It produces flight and ground profiles and lists of key parameters. These outputs inform about expected SAR image characteristics and can be employed for optimization of the planning. Using this tool, a non-specialist can perform a robust planning of SAR acquisitions. VDE VERLAG GMBH • Berlin • Offenbach.
BibTeX:
@conference{Magnard20181052,
  author = {Magnard, C. and Wegmüller, U. and Werner, C. and Bonvin, F. and Meier, E.},
  title = {Planning tool for SAR missions},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-June},
  pages = {1052-1057},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050505782&partnerID=40&md5=cc483818aff21c4d87e3e28fc76776aa}
}
Manconi A, Coviello V, Galletti M and Seifert R (2018), "Short communication: Monitoring rockfalls with the Raspberry Shake", Earth Surface Dynamics. Vol. 6(4), pp. 1219-1227. Copernicus GmbH.
Abstract: We evaluate the performance of the low-cost seismic sensor Raspberry Shake to identify and monitor rockfall activity in alpine environments. The test area is a slope adjacent to the Great Aletsch Glacier in the Swiss Alps, i.e. the Moosfluh deep-seated instability, which has recently undergone a critical acceleration phase. A local seismic network composed of three Raspberry Shake was deployed starting from May 2017 in order to record rockfall activity and its relation with the progressive rock-slope degradation potentially leading to a large rock-slope failure. Here we present a first assessment of the seismic data acquired from our network after a monitoring period of 1 year. We show that our network performed well during the whole duration of the experiment, including the winter period in severe alpine conditions, and that the seismic data acquired allowed us to clearly discriminate between rockfalls and other events. This work also provides general information on the potential use of such low-cost sensors in environmental seismology. 2018 Author(s).
BibTeX:
@article{Manconi20181219,
  author = {Manconi, A. and Coviello, V. and Galletti, M. and Seifert, R.},
  title = {Short communication: Monitoring rockfalls with the Raspberry Shake},
  journal = {Earth Surface Dynamics},
  publisher = {Copernicus GmbH},
  year = {2018},
  volume = {6},
  number = {4},
  pages = {1219-1227},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058557157&doi=10.5194%2fesurf-6-1219-2018&partnerID=40&md5=434f613d5d9202ff085be2ee61b196ba},
  doi = {10.5194/esurf-6-1219-2018}
}
Manconi A, Kourkouli P, Caduff R, Strozzi T and Loew S (2018), "Monitoring surface deformation over a failing rock slope with the ESA sentinels: Insights from Moosfluh instability, Swiss Alps", Remote Sensing. Vol. 10(5) MDPI AG.
Abstract: We leverage on optical and radar remote sensing data acquired from the European Space Agency (ESA) Sentinels to monitor the surface deformation evolution on a large and very active instability located in the Swiss Alps, i.e., the Moosfluh rock slope. In the late summer 2016, a sudden acceleration was reported at this location, with surface velocity rates passing from maximum values of 0.2 cm/day to 80 cm/day. A dense pattern of uphill-facing scarps and tension cracks formed within the instability and rock fall activity started to become very pronounced. This evolution of the rock mass may suggest that the most active portion of the slope could fail catastrophically. Here we discuss advantages and limitations of the use of spaceborne methods for hazard analyses and early warning by using the ESA Sentinels, and show that in critical scenarios they are often not sufficient to reliably interpret the evolution of surface deformation. The insights obtained from this case study are relevant for similar scenarios in the Alps and elsewhere. 2018 by the authors.
BibTeX:
@article{Manconi2018,
  author = {Manconi, A. and Kourkouli, P. and Caduff, R. and Strozzi, T. and Loew, S.},
  title = {Monitoring surface deformation over a failing rock slope with the ESA sentinels: Insights from Moosfluh instability, Swiss Alps},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {5},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047514503&doi=10.3390%2frs10050672&partnerID=40&md5=b2da4c0ea1504183ba7cbbd97c4e529a},
  doi = {10.3390/rs10050672}
}
Mattia F, Balenzano A, Satalino G, Lovergine F, Peng J, Wegmüller U, Cartus O, Davidson M, Kim S, Johnson J, Walker J, Wu X, Pauwels V, McNairn H, Caldwell T, Cosh M and Jackson T (2018), "Sentinel-1 and Sentinel-2 for soil moisture retrieval at field scale", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6143-6146. Institute of Electrical and Electronics Engineers Inc..
Abstract: Soil moisture content is an essential climate variable that is operationally delivered at low resolution (e.g. 36-9 ) by earth observation missions, such as ESA/SMOS, NASA/SMAP and EUMETSAT/ASCAT. However numerous land applications would benefit from the availability of soil moisture maps at higher resolution. For this reason, there is a large research effort to develop soil moisture products at higher resolution using, for instance, data acquired by the new ESA's Sentinel missions. The objective of this study is twofold. First, it presents the validation status of a pre-operational soil moisture product derived from Sentinel-1 at 1 resolution. Second, it assesses the possibility of integrating Sentinel-2 data and additional ancillary information, such as parcel borders and high resolution soil texture maps, in order to obtain soil moisture maps at “field scale” resolution, i.e.  0.1 . Case studies concerning agricultural sites located in Europe are presented. 2018 IEEE
BibTeX:
@conference{Mattia20186143,
  author = {Mattia, F. and Balenzano, A. and Satalino, G. and Lovergine, F. and Peng, J. and Wegmüller, U. and Cartus, O. and Davidson, M.W.J. and Kim, S. and Johnson, J. and Walker, J. and Wu, X. and Pauwels, V.R.N. and McNairn, H. and Caldwell, T. and Cosh, M. and Jackson, T.},
  title = {Sentinel-1 and Sentinel-2 for soil moisture retrieval at field scale},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6143-6146},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063160566&doi=10.1109%2fIGARSS.2018.8518170&partnerID=40&md5=2aa1be526dccb673af6069f7d0e8810e},
  doi = {10.1109/IGARSS.2018.8518170}
}
Molg N, Bolch T, Rastner P, Strozzi T and Paul F (2018), "A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: Distribution of debris cover and mapping challenges", Earth System Science Data. Vol. 10(4), pp. 1807-1827. Copernicus GmbH.
Abstract: Knowledge about the coverage and characteristics of glaciers in High Mountain Asia (HMA) is still incomplete and heterogeneous. However, several applications, such as modelling of past or future glacier development, run-off, or glacier volume, rely on the existence and accessibility of complete datasets. In particular, precise outlines of glacier extent are required to spatially constrain glacier-specific calculations such as length, area, and volume changes or flow velocities. As a contribution to the Randolph Glacier Inventory (RGI) and the Global Land Ice Measurements from Space (GLIMS) glacier database, we have produced a homogeneous inventory of the Pamir and the Karakoram mountain ranges using 28 Landsat TM and ETM+ scenes acquired around the year 2000. We applied a standardized method of automated digital glacier mapping and manual correction using coherence images from the Advanced Land Observing Satellite 1 (ALOS-1) Phased Array type L-band Synthetic Aperture Radar 1 (PALSAR-1) as an additional source of information; we then (i) separated the glacier complexes into individual glaciers using drainage divides derived by watershed analysis from the ASTER global digital elevation model version 2 (GDEM2) and (ii) separately delineated all debris-covered areas. Assessment of uncertainties was performed for debris-covered and clean-ice glacier parts using the buffer method and independent multiple digitizing of three glaciers representing key challenges such as shadows and debris cover. Indeed, along with seasonal snow at high elevations, shadow and debris cover represent the largest uncertainties in our final dataset. In total, we mapped more than 27 800 glaciers &gt; 0.02 km2 covering an area of 35 520±1948 km2 and an elevation range from 2260 to 8600 m. Regional median glacier elevations vary from 4150 m (Pamir Alai) to almost 5400 m (Karakoram), which is largely due to differences in temperature and precipitation. Supraglacial debris covers an area of 3587±662 km2, i.e. 10 % of the total glacierized area. Larger glaciers have a higher share in debris-covered area (up to &gt; 20 %), making it an important factor to be considered in subsequent applications (https://doi.org/10.1594/PANGAEA.894707). Author(s) 2018.
BibTeX:
@article{Molg20181807,
  author = {Molg, N. and Bolch, T. and Rastner, P. and Strozzi, T. and Paul, F.},
  title = {A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: Distribution of debris cover and mapping challenges},
  journal = {Earth System Science Data},
  publisher = {Copernicus GmbH},
  year = {2018},
  volume = {10},
  number = {4},
  pages = {1807-1827},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054693653&doi=10.5194%2fessd-10-1807-2018&partnerID=40&md5=1f2fac41d05ce3abf3eb07d14a7070a2},
  doi = {10.5194/essd-10-1807-2018}
}
Naderpour R and Schwank M (2018), "Snow wetness retrieved from L-band radiometry", Remote Sensing. Vol. 10(3) MDPI AG.
Abstract: The present study demonstrates the successful use of the high sensitivity of L-band brightness temperatures to snow liquid water in the retrieval of snow liquid water from multi-angular L-band brightness temperatures. The emission model employed was developed from parts of the "microwave emission model of layered snowpacks" (MEMLS), coupled with components adopted from the "L-band microwave emission of the biosphere" (L-MEB) model. Two types of snow liquid water retrievals were performed based on L-band brightness temperatures measured over (i) areas with a metal reflector placed on the ground ("reflector area"-TB, R), and (ii) natural snow-covered ground ("natural area"-TB, N). The reliable representation of temporal variations of snow liquid water is demonstrated for both types of the aforementioned quasi-simultaneous retrievals. This is verified by the fact that both types of snow liquid water retrievals indicate a dry snowpack throughout the "cold winter period" with frozen ground and air temperatures well below freezing, and synchronously respond to snowpack moisture variations during the "early spring period". The robust and reliable performance of snow liquid water retrieved from TB, R, together with their level of detail, suggest the use of these retrievals as "references" to assess the meaningfulness of the snow liquid water retrievals based on TB, N. It is noteworthy that the latter retrievals are achieved in a two-step retrieval procedure using exclusively L-band brightness temperatures, without the need for in-situ measurements, such as ground permittivity εG and snow mass-density ρS. The latter two are estimated in the first retrieval-step employing the well-established two-parameter (ρS, εG) retrieval scheme designed for dry snow conditions and explored in the companion paper that is included in this special issue in terms of its sensitivity with respect to disturbative melting effects. The two-step retrieval approach proposed and investigated here, opens up the possibility of using airborne or spaceborne L-band radiometry to estimate (ρS,εG) and additionally snow liquid water as a new passive L-band data product. 2018 by the authors.
BibTeX:
@article{Naderpour2018,
  author = {Naderpour, R. and Schwank, M.},
  title = {Snow wetness retrieved from L-band radiometry},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {3},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042526532&doi=10.3390%2frs10030359&partnerID=40&md5=c13e5cf6596f34fa1d0216592fd6df44},
  doi = {10.3390/rs10030359}
}
Naderpour R and Schwank M (2018), "Snow wetness retrieved from L-band radiometry", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 1466-1469. Institute of Electrical and Electronics Engineers Inc..
Abstract: The present study demonstrates the successful use of L-band brightness temperatures to retrieve snow liquid water from multi-angular measurements . The emission model employed was developed from parts of the “microwave emission model of layered snowpacks” (MEMLS) coupled with components adopted from the “L-band microwave emission of the biosphere” (L-MEB) model. Two types of snow liquid water retrievals were performed based on measured over i) areas with a metal reflector placed on the ground (“reflector area”- ), and ii) natural snow-covered ground (“natural area”- ). The reliable representation of temporal variations of snow liquid water is demonstrated for both types of retrievals. This is verified by the fact that both types of - retrievals indicate a dry snowpack throughout the “cold winter period” with frozen ground and air temperatures well below freezing, and synchronously respond to snowpack moisture variations during the “early spring period”. Snow liquid water retrievals based on are achieved in a two-step retrieval procedure using exclusively L-band brightness temperatures, without the need for in-situ measurements such as ground permittivity and snow mass-density . The latter two are estimated in the first retrieval-step employing the well-established two-parameter , retrieval scheme. The proposed and investigated two-step retrieval approach opens up the possibility of using airborne or spaceborne L-band radiometry to estimate. 2018 IEEE
BibTeX:
@conference{Naderpour20181466,
  author = {Naderpour, R. and Schwank, M.},
  title = {Snow wetness retrieved from L-band radiometry},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {1466-1469},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064157491&doi=10.1109%2fIGARSS.2018.8518614&partnerID=40&md5=b728fc8fcd5ace5c59d56ac3f054b084},
  doi = {10.1109/IGARSS.2018.8518614}
}
Roy A, Leduc-Leballeur M, Picard G, Royer A, Toose P, Derksen C, Lemmetyinen J, Berg A, Rowlandson T and Schwank M (2018), "Modelling the L-band Snow-covered surface emission in a winter Canadian prairie environment", Remote Sensing. Vol. 10(9) MDPI AG.
Abstract: Detailed angular ground-based L-band brightness temperature (TB) measurements over snow covered frozen soil in a prairie environment were used to parameterize and evaluate an electromagnetic model, the Wave Approach for LOw-frequency MIcrowave emission in Snow (WALOMIS), for seasonal snow. WALOMIS, initially developed for Antarctic applications, was extended with a soil interface model. A Gaussian noise on snow layer thickness was implemented to account for natural variability and thus improve the TB simulations compared to observations. The model performance was compared with two radiative transfer models, the Dense Media Radiative Transfer-Multi Layer incoherent model (DMRT-ML) and a version of the Microwave Emission Model for Layered Snowpacks (MEMLS) adapted specifically for use at L-band in the original one-layer configuration (LS-MEMLS-1L). Angular radiometer measurements (30°, 40°, 50°, and 60°) were acquired at six snow pits. The root-mean-square error (RMSE) between simulated and measured TB at vertical and horizontal polarizations were similar for the three models, with overall RMSE between 7.2 and 10.5 K. However, WALOMIS and DMRT-ML were able to better reproduce the observed TB at higher incidence angles (50° and 60°) and at horizontal polarization. The similar results obtained betweenWALOMIS and DMRT-ML suggests that the interference phenomena are weak in the case of shallow seasonal snow despite the presence of visible layers with thicknesses smaller than the wavelength, and the radiative transfer model can thus be used to compute L-band brightness temperature. 2018 by the authors.
BibTeX:
@article{Roy2018,
  author = {Roy, A. and Leduc-Leballeur, M. and Picard, G. and Royer, A. and Toose, P. and Derksen, C. and Lemmetyinen, J. and Berg, A. and Rowlandson, T. and Schwank, M.},
  title = {Modelling the L-band Snow-covered surface emission in a winter Canadian prairie environment},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {9},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053599745&doi=10.3390%2frs10091451&partnerID=40&md5=3d568e815c2518c0b8b041c81f09b160},
  doi = {10.3390/rs10091451}
}
Santoro M and Cartus O (2018), "Research pathways of forest above-ground biomass estimation based on SAR backscatter and interferometric SAR observations", Remote Sensing. Vol. 10(4) MDPI AG.
Abstract: Estimation of forest biomass with synthetic aperture radar (SAR) and interferometric SAR (InSAR) observables has been surveyed in 186 peer-reviewed papers to identify major research pathways in terms of data used and retrieval models. Research evaluated primarily (i) L-band observations of SAR backscatter; and, (ii) single-image or multi-polarized retrieval schemes. The use of multi-temporal or multi-frequency data improved the biomass estimates when compared to single-image retrieval. Low frequency SAR backscatter contributed the most to the biomass estimates. Single-pass InSAR height was reported to be a more reliable predictor of biomass, overcoming the loss of sensitivity of SAR backscatter and coherence in high biomass forest. A variety of empirical and semi-empirical regression models relating biomass to the SAR observables were proposed. Semi-empirical models were mostly used for large-scale mapping because of the simple formulation and the robustness of the model parameters estimates to forest structure and environmental conditions. Non-parametric models were appraised for their capability to ingest multiple observations and perform accurate retrievals having a large number of training samples available. Some studies argued that estimating compartment biomass (in stems, branches, foliage) with different types of SAR observations would lead to an improved estimate of total biomass. Although promising, scientific evidence for such an assumption is still weak. The increased availability of free and open SAR observations from currently orbiting and forthcoming spaceborne SAR missions will foster studies on forest biomass retrieval. Approaches attempting to maximize the information content on biomass of individual data streams shall be pursued. 2018 by the authors.
BibTeX:
@article{Santoro2018,
  author = {Santoro, M. and Cartus, O.},
  title = {Research pathways of forest above-ground biomass estimation based on SAR backscatter and interferometric SAR observations},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045999782&doi=10.3390%2frs10040608&partnerID=40&md5=fcef84234f3e46ef9b97bb153cc4d802},
  doi = {10.3390/rs10040608}
}
Santoro M, Wegmüller U and Askne J (2018), "Forest stem volume estimation using C-band interferometric SAR coherence data of the ERS-1 mission 3-days repeat-interval phase", Remote Sensing of Environment. Vol. 216, pp. 684-696. Elsevier Inc..
Abstract: Interferometric synthetic aperture radar (InSAR) coherence datasets from the 3-days phase of the European Remote Sensing Satellite (ERS-1) mission during the winter months of 1992 have been analyzed to assess the capability to retrieve forest stem volume in boreal forests. For three test sites in Sweden and Finland, coherence decreased for increasing repeat-pass interval from 3- to 12-days due to increasing temporal decorrelation. Overall strong decorrelation was observed for images acquired under unfrozen conditions or thawing conditions. Coherence was best preserved under stable frozen conditions and, in addition, short perpendicular component of the interferometric baseline (i.e., &lt;300 m). Stem volume was estimated with the Interferometric Water Cloud Model (IWCM) and multi-temporal combination of single-image estimates. For the test site of Tuusula, Finland, data from eight 3-days image pairs yielded a relative RMSE of 28.2% for stem volumes ranging between 3 and 482 m3/ha. For the 6-days repeat-pass interval, the relative RMSE was only slightly worse (32.4%). For longer repeat-pass intervals, the relative RMSE was above 50%. This study suggests that C-band short-term coherence has potential to support retrieval of forest biomass but the prospects of Sentinel-1 coherence to estimate biomass appear to be limited to the 6-days coherence in areas characterized by stable frozen, or likewise stable dry, conditions. 2018 Elsevier Inc.
BibTeX:
@article{Santoro2018684,
  author = {Santoro, M. and Wegmüller, U. and Askne, J.},
  title = {Forest stem volume estimation using C-band interferometric SAR coherence data of the ERS-1 mission 3-days repeat-interval phase},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2018},
  volume = {216},
  pages = {684-696},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050944421&doi=10.1016%2fj.rse.2018.07.032&partnerID=40&md5=a329952686b15530f77fc9526957c4c0},
  doi = {10.1016/j.rse.2018.07.032}
}
Schwank M and Naderpour R (2018), "Snow density and ground permittivity retrieved from L-band radiometry: Melting effects", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 1245-1248. Institute of Electrical and Electronics Engineers Inc..
Abstract: Ground permittivity and snow density retrievals are performed using the tower-based experimental L-band radiometry data from the winter 2016/2017 campaign at the Davos-Laret Remote Sensing Field Laboratory. The performance of multi-angle two-parameter retrieval algorithms to estimate snow density and ground permittivity PRM = (?SRM, eGRM) is assessed using in-situ measured eG and ?S. Additionally, a synthetic retrieval sensitivity analysis is conducted which studies impacts of “melting effects” on retrievals (?SRM, eGRM) in the form of snow liquid water. Experimental and synthetic analyses show that snow liquid water noticeably disturbs the retrievals and result in increased correlation R2(?SRM, eGRM) between them. The strength of this correlation is used as a quality-indicator flag to filter out highly correlated retrieval pairs. It is demonstrated that this filtering significantly improves the accuracy of both ground permittivity and snow density retrievals compared to corresponding reference in-situ data. Our analysis shows that retrievals P "V"= (?S"V" , eG "V") using vertical polarization only (RM = “V”) are predominantly least prone to snow liquid water. The presented experimental results indicate that retrievals match in-situ observations best for the “snow-free period” and the “cold winter period” when snow liquid water is at minimum. 2018 IEEE
BibTeX:
@conference{Schwank20181245,
  author = {Schwank, M. and Naderpour, R.},
  title = {Snow density and ground permittivity retrieved from L-band radiometry: Melting effects},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {1245-1248},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063125521&doi=10.1109%2fIGARSS.2018.8517581&partnerID=40&md5=e8a333e472b09d6b761e5b2bd2eb5e46},
  doi = {10.1109/IGARSS.2018.8517581}
}
Schwank M and Naderpour R (2018), "Snow density and ground permittivity retrieved from L-band radiometry: Melting effects", Remote Sensing. Vol. 10(2) MDPI AG.
Abstract: Ground permittivity and snow density retrievals for the "snow-free period", "cold winter period", and "early spring period" are performed using the experimental L-band radiometry data from the winter 2016/2017 campaign at the Davos-Laret Remote Sensing Field Laboratory. The performance of the single-angle and multi-angle two-parameter retrieval algorithms employed during each of the aforementioned three periods is assessed using in-situ measured ground permittivity and snow density. Additionally, a synthetic sensitivity analysis is conducted that studies melting effects on the retrievals in the form of two types of "geophysical noise" (snow liquid water and footprint-dependent ground permittivity). Experimental and synthetic analyses show that both types of investigated "geophysical noise" noticeably disturb the retrievals and result in an increased correlation between them. The strength of this correlation is successfully used as a quality-indicator flag for the purpose of filtering out highly correlated ground permittivity and snow density retrievals. It is demonstrated that this filtering significantly improves the accuracy of both ground permittivity and snow density retrievals compared to corresponding reference in-situ data. Experimental and synthetic retrievals are performed in retrieval modes RM = "H", "V", and "HV", where brightness temperatures from polarizations p = H, p = V, or both p = H and V are used, respectively, in the retrieval procedure. Our analysis shows that retrievals for RM = "V" are predominantly least prone to the investigated "geophysical noise". The presented experimental results indicate that retrievals match in-situ observations best for the "snow-free period" and the "cold winter period" when "geophysical noise" is at minimum. 2018 by the authors.
BibTeX:
@article{Schwank2018c,
  author = {Schwank, M. and Naderpour, R.},
  title = {Snow density and ground permittivity retrieved from L-band radiometry: Melting effects},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {2},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042548031&doi=10.3390%2frs10020354&partnerID=40&md5=3f983b1467000c85ab28719c5622297a},
  doi = {10.3390/rs10020354}
}
Schwank M, Naderpour R and Matzler C (2018), "Tau-Omega - and Two-Stream emission models used for passive L-Band retrievals: Application to close-range measurements over a forest", Remote Sensing. Vol. 10(12) MDPI AG.
Abstract: Microwave Emission Models (EM) are used in retrieval algorithms to estimate geophysical state parameters such as soil Water Content (WC) and vegetation optical depth (τ), from brightness temperatures T B p,θ measured at nadir angles θ at Horizontal and Vertical polarizations p = (H,V). An EM adequate for implementation in a retrieval algorithm must capture the responses of T B p,θ to the retrieval parameters, and the EM parameters must be experimentally accessible and representative of the measurement footprint. The objective of this study is to explore the benefits of the multiple-scattering Two-Stream (2S) EM over the "Tau-Omega" (TO) EM considered as the "reference" to retrieve WC and τ from L-band T B p,θ . For sparse and low-scattering vegetation T B,EM p,θ simulated with EM = (TO, 2S) converge. This is not the case for dense and strongly scattering vegetation. Two-Parameter (2P) retrievals 2P RC = (WC RC , τ RC ) are computed from elevation scans T B p,θj = T B TO p,θj , synthesized with TO EM and from T B p,θj measured from a tower within a deciduous forest. Retrieval Configurations (RC) employ either EM = TO or EM = 2S and assume fixed scattering albedos. WC RC achieved with the 2S RC is marginally lower ( 1 m 3 m -3 ) than if achieved with the "reference" TO RC, while τRC is reduced considerably when using 2S EM instead of TO EM. Our study outlines a number of advantages of the 2S EM over the TO EM currently implemented in the operational SMOS and SMAP retrieval algorithms. 2018 by the authors.
BibTeX:
@article{Schwank2018a,
  author = {Schwank, M. and Naderpour, R. and Matzler, C.},
  title = {Tau-Omega - and Two-Stream emission models used for passive L-Band retrievals: Application to close-range measurements over a forest},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {12},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85057073180&doi=10.3390%2frs10121868&partnerID=40&md5=f232f9c088c32b690dbab8274b1aff78},
  doi = {10.3390/rs10121868}
}
Siddique M, Strozzi T, Hajnsek I and Frey O (2018), "A case study on the correction of atmosphere-induced phase disturbances for SAR tomography in mountainous areas", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2018-June, pp. 1412-1416. Institute of Electrical and Electronics Engineers Inc..
Abstract: The estimation of the atmosphere-induced phase delay variations is often more involved in mountainous areas due to strong spatial variations of the local atmospheric conditions and propagation paths through the troposphere. Height-dependent phase delay variation owing to vertical stratification of the atmosphere within the same range-azimuth resolution cell cannot be ignored. We propose a regression kriging-based data-driven method whereby phase corrections are applied for differential tomographic focusing at each 3D point of interest along the elevation axis. Experiments are performed on an interferometric stack comprising 32 Cosmo-SkyMed stripmap images acquired between 2008-2013 over the Matter Valley in the Swiss Alps. VDE VERLAG GMBH  Berlin  Offenbach.
BibTeX:
@conference{Siddique20181412,
  author = {Siddique, M.A. and Strozzi, T. and Hajnsek, I. and Frey, O.},
  title = {A case study on the correction of atmosphere-induced phase disturbances for SAR tomography in mountainous areas},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-June},
  pages = {1412-1416},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050480326&partnerID=40&md5=7db583599ee5407243c22a4dc2d1d530}
}
Siddique M, Strozzi T, Hajnsek I and Frey O (2018), "SAR tomography for spatio-temporal inversion of coherent scatterers in villages of alpine regions", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 6099-6102. Institute of Electrical and Electronics Engineers Inc..
Abstract: Differential synthetic aperture radar (SAR) tomography allows separation of multiple coherent scatterers interfering in the same range-azimuth resolution cell as well as the estimation of the deformation parameters of each scatterer. In this way, the spatio-temporal tomographic inversion serves as a means to resolve the layover and simultaneously improve deformation sampling. Compared to metropolitan regions with several man-made structures, the prevalence of coherent scatterers in the villages of alpine regions is generally low, while at the same time layovers are widespread due to the ruggedness of the terrain. Moreover, the drastic height variations in the imaged scene necessitate height-dependent compensation of the atmospheric phase delay variations within the tomographic inversion. This paper addresses these concerns while performing experiments on an interferometric stack comprising 33 Cosmo-SkyMed strimap images acquired in the summers between 2008-13 over Matter Valley in the Swiss Alps. The results show improved deformation sampling along the layover-affected mountainside.
BibTeX:
@conference{Siddique20186099,
  author = {Siddique, M.A. and Strozzi, T. and Hajnsek, I. and Frey, O.},
  title = {SAR tomography for spatio-temporal inversion of coherent scatterers in villages of alpine regions},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {6099-6102},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063144918&doi=10.1109%2fIGARSS.2018.8518296&partnerID=40&md5=b5d471786810f929686579ba84aaadc2},
  doi = {10.1109/IGARSS.2018.8518296}
}
Siddique M, Wegmüller U, Hajnsek I and Frey O (2018), "SAR tomography as an add-On to PSI: Detection of coherent scatterers in the presence of phase instabilities", Remote Sensing. Vol. 10(7) MDPI AG.
Abstract: The estimation of deformation parameters using persistent scatterer interferometry (PSI) is limited to single dominant coherent scatterers. As such, it rejects layovers wherein multiple scatterers are interfering in the same range-azimuth resolution cell. Differential synthetic aperture radar (SAR) tomography can improve deformation sampling as it has the ability to resolve layovers by separating the interfering scatterers. In this way, both PSI and tomography inevitably require a means to detect coherent scatterers, i.e., to perform hypothesis testing to decide whether a given candidate scatterer is coherent. This paper reports the application of a detection strategy in the context of "tomography as an add-on to PSI". As the performance of a detector is typically linked to the statistical description of the underlying mathematical model, we investigate how the statistics of the phase instabilities in the PSI analysis are carried forward to the subsequent tomographic analysis. While phase instabilities in PSI are generally modeled as an additive noise term in the interferometric phase model, their impact in SAR tomography manifests as a multiplicative disturbance. The detection strategy proposed in this paper allows extending the same quality considerations as used in the prior PSI processing (in terms of the dispersion of the residual phase) to the subsequent tomographic analysis. In particular, the hypothesis testing for the detection of coherent scatterers is implemented such that the expected probability of false alarm is consistent between PSI and tomography. The investigation is supported with empirical analyses on an interferometric data stack comprising 50 TerraSAR-X acquisitions in stripmap mode, over the city of Barcelona, Spain, from 2007-2012. 2018 by the authors.
BibTeX:
@article{Siddique2018,
  author = {Siddique, M.A. and Wegmüller, U. and Hajnsek, I. and Frey, O.},
  title = {SAR tomography as an add-On to PSI: Detection of coherent scatterers in the presence of phase instabilities},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {7},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050493688&doi=10.3390%2frs10071014&partnerID=40&md5=ae2dd4d2a33491a409c4e9a1806e0203},
  doi = {10.3390/rs10071014}
}
Smolander T, Lemmetyinen J, Rautiainen K, Schwank M and Pulliainen J (2018), "Soil permittivity and soil frost retrievals using a synergistic method for active and passive microwave instruments", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2018-July, pp. 7782-7784. Institute of Electrical and Electronics Engineers Inc..
Abstract: A synergistic method for obtaining soil permittivity and soil frost was developed. The method incorporates a semiempirical backscattering model for forested land. Soil permittivity is retrieved from active microwave observations using least squares inversion method. Bayesian assimilation scheme can be applied to combine the active retrieval with a permittivity estimate from a passive instrument. Soil frost can be determined from permittivity estimates using a threshold method. The synergistic method was tested on boreal forest site in Northern Finland using ASAR for active and SMOS for passive observations. Satellite retrievals were compared to in situ soil permittivity, temperature and frost measurements. The results show that high resolution SAR data (e.g., ASAR, Sentinel) can be used to downscale coarse resolution SMOS estimates and that synergistic method reduces variability and biases of the ASAR retrieval. 2018 IEEE
BibTeX:
@conference{Smolander20187782,
  author = {Smolander, T. and Lemmetyinen, J. and Rautiainen, K. and Schwank, M. and Pulliainen, J.},
  title = {Soil permittivity and soil frost retrievals using a synergistic method for active and passive microwave instruments},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {2018-July},
  pages = {7782-7784},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063128002&doi=10.1109%2fIGARSS.2018.8517284&partnerID=40&md5=086282facf56d31394a6143402c0c9ad},
  doi = {10.1109/IGARSS.2018.8517284}
}
Strozzi T, Antonova S, Gunther F, Matzler E, Vieira G, Wegmüller U, Westermann S and Bartsch A (2018), "Sentinel-1 SAR interferometry for surface deformation monitoring in low-land permafrost areas", Remote Sensing. Vol. 10(9) MDPI AG.
Abstract: Low-land permafrost areas are subject to intense freeze-thaw cycles and characterized by remarkable surface displacement. We used Sentinel-1 SAR interferometry (InSAR) in order to analyse the summer surface displacement over four spots in the Arctic and Antarctica since 2015. Choosing floodplain or outcrop areas as the reference for the InSAR relative deformation measurements, we found maximum subsidence of about 3 to 10 cm during the thawing season with generally high spatial variability. Sentinel-1 time-series of interferograms with 6-12 day time intervals highlight that subsidence is often occurring rather quickly within roughly one month in early summer. Intercomparison of summer subsidence from Sentinel-1 in 2017 with TerraSAR-X in 2013 over part of the Lena River Delta (Russia) shows a high spatial agreement between both SAR systems. A comparison with in-situ measurements for the summer of 2014 over the Lena River Delta indicates a pronounced downward movement of several centimetres in both cases but does not reveal a spatial correspondence between InSAR and local in-situ measurements. For the reconstruction of longer time-series of deformation, yearly Sentinel-1 interferograms from the end of the summer were considered. However, in order to infer an effective subsidence of the surface through melting of excess ice layers over multi-annual scales with Sentinel-1, a longer observation time period is necessary. 2018 by the authors.
BibTeX:
@article{Strozzi2018,
  author = {Strozzi, T. and Antonova, S. and Gunther, F. and Matzler, E. and Vieira, G. and Wegmüller, U. and Westermann, S. and Bartsch, A.},
  title = {Sentinel-1 SAR interferometry for surface deformation monitoring in low-land permafrost areas},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {9},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053610234&doi=10.3390%2frs10091360&partnerID=40&md5=c917688c8f189ddf1bb79e4028229b2a},
  doi = {10.3390/rs10091360}
}
Strozzi T, Klimeš J, Frey H, Caduff R, Huggel C, Wegmüller U and Rapre A (2018), "Satellite SAR interferometry for the improved assessment of the state of activity of landslides: A case study from the Cordilleras of Peru", Remote Sensing of Environment. Vol. 217, pp. 111-125. Elsevier Inc..
Abstract: In Peru landslides have been causing damages and casualties annually due to the high mountain relief and distinct seasonal precipitation distribution. Satellite Synthetic Aperture Radar (SAR) interferometry represents one possibility for mapping surface deformation at fine spatial resolution over large areas in order to characterize aspects of terrain motion and potentially hazardous processes. We present land surface motion maps derived from satellite SAR interferometry (InSAR) for a part of the Santa River Basin between the Cordilleras Blanca and Negra around the city of Carhuaz in Peru. Using both Persistent Scatterer Interferometry (PSI) and differential SAR Interferograms (DInSAR) from ALOS-1 PALSAR-1, ENVISAT ASAR, ALOS-2 PALSAR-2 and Sentinel-1 we mapped 42 landslides extending over 17,190,141 m2 within three classes of activity (i.e. 0–2 cm/a, 2–10 cm/a and &gt;10 cm/a). A geomorphological inventory of landslides was prepared from optical satellite imagery and field experience and compared to the InSAR-based slope-instability inventory. The two approaches provide slightly different information about landslide spatial and temporal activity patterns, but altogether they can be combined for the assessment of the state of activity of landslides and possibly the development of hazard maps, which are not systematically available in this region. We conclude that ALOS PALSAR (1 and 2) and Sentinel-1 data have a high potential to derive high-quality surface deformation information of landslides in many mountainous regions worldwide due to their global and frequent acquisition strategies. 2018
BibTeX:
@article{Strozzi2018111,
  author = {Strozzi, T. and Klimeš, J. and Frey, H. and Caduff, R. and Huggel, C. and Wegmüller, U. and Rapre, A.C.},
  title = {Satellite SAR interferometry for the improved assessment of the state of activity of landslides: A case study from the Cordilleras of Peru},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2018},
  volume = {217},
  pages = {111-125},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051411956&doi=10.1016%2fj.rse.2018.08.014&partnerID=40&md5=ed7b88e6ed042e6af798778cd56ab5f5},
  doi = {10.1016/j.rse.2018.08.014}
}
Tosi L, Da Lio C, Teatini P and Strozzi T (2018), "Land subsidence in coastal environments: Knowledge advance in the Venice coastland by TerraSAR-X PSI", Remote Sensing. Vol. 10(8) MDPI AG.
Abstract: The use of satellite SAR interferometric methods has significantly improved the monitoring of ground movements over the last decades, thus opening new possibilities for a more accurate interpretation of land subsidence and its driving mechanisms. TerraSAR-X has been extensively used to study land subsidence in the Venice Lagoon, Italy, with the aim of quantifying the natural and anthropogenic causes. In this paper, we review and update the main results achieved by three research projects supported by DLR AOs (German Aerospace Center Announcement of Opportunity) and conducted to test the capability of TerraSAR-X PSI (Persistent Scatterer Interferometry) to detect ground movements in the complex physiographic setting of the Venice transitional coastal environment. The investigations have been focused on the historical center of Venice, the lagoon inlets where the MoSE is under construction, salt marshes, and newly built-up areas in the littoral. PSI on stacks of stripmap TerraSAR-X images covering short- to long-time periods (i.e., the years 2008-2009, 2008-2011 and 2008-2013) has proven particularly effective to measure land subsidence in the Venice coastland. The very high spatial resolution (3 m) and the short repeat time interval (11 days) of the TerraSAR-X acquisitions make it possible to investigate ground movements with a detail unavailable in the past. The interferometric products, properly calibrated, allowed for a millimetric vertical accuracy of the land movements at both the regional and local scales, even for short-term analyses, i.e., spanning one year only. The new picture of the land movement resulted from processing TerraSAR-X images has significantly contributed to update the knowledge on the subsidence process at the Venice coast. 2018 by the authors.
BibTeX:
@article{Tosi2018,
  author = {Tosi, L. and Da Lio, C. and Teatini, P. and Strozzi, T.},
  title = {Land subsidence in coastal environments: Knowledge advance in the Venice coastland by TerraSAR-X PSI},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2018},
  volume = {10},
  number = {8},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051656903&doi=10.3390%2frs10081191&partnerID=40&md5=3e47f55707851ad9a7f6854b2f23670e},
  doi = {10.3390/rs10081191}
}
Wegmüller U, Werner C, Frey O, Magnard C and Strozzi T (2018), "Reformulating the split-spectrum method to facilitate the estimation and compensation of the ionospheric phase in SAR interferograms", Procedia Computer Science. Vol. 138, pp. 318-325. Elsevier B.V..
Abstract: Spatial and temporal variation of the free electron concentration in the ionosphere affects SAR interferograms, in particular at low radar frequencies. The split-spectrum method permits separating the ionospheric and the non-dispersive phase terms using spectral sub-band images. In this work a reformulation of the split-spectrum method facilitates the necessary processing steps. Reformulating the split-spectrum method permits determining the ionospheric phase component based on a split-spectrum double-difference interferogram and the full-bandwidth differential interferogram. In this way differing a pair of unwrapped phase images, each one scaled by a large factor, can be avoided, making the method more robust. The applicability of the proposed method is demonstrated with examples including cases with very strong ionospheric effects. 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.
BibTeX:
@article{Wegmuller2018318,
  author = {Wegmüller, U. and Werner, C. and Frey, O. and Magnard, C. and Strozzi, T.},
  title = {Reformulating the split-spectrum method to facilitate the estimation and compensation of the ionospheric phase in SAR interferograms},
  journal = {Procedia Computer Science},
  publisher = {Elsevier B.V.},
  year = {2018},
  volume = {138},
  pages = {318-325},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061975908&doi=10.1016%2fj.procs.2018.10.045&partnerID=40&md5=d0cbc9cb7116a40996e2a6bc00df0d1e},
  doi = {10.1016/j.procs.2018.10.045}
}
Zhang B, Ding X, Werner C, Tan K, Zhang B, Jiang M, Zhao J and Xu Y (2018), "Dynamic displacement monitoring of long-span bridges with a microwave radar interferometer", ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 138, pp. 252-264. Elsevier B.V..
Abstract: Structural health monitoring of long-span bridges is a critical process in ensuring the operational safety of the structures. In this paper, we present experimental results of monitoring the displacements of two long-span bridges in Hong Kong Ting Kau Bridge (TKB) and Tsing Ma Bridge (TMB) with a terrestrial microwave radar interferometer named the GAMMA Portable Radar Interferometer (GPRI). A technique for fusing the measurements from two receiving antennas of the radar instrument is proposed. In addition, a two-step phase unwrapping approach is also tested. The results reveal the bridge dynamic responses under different loading conditions, including winds, vehicle traffic, and passing trains. The results also show that the terrestrial microwave radar interferometer can be used to monitor the dynamics of long-span bridges with unprecedented spatial and temporal resolutions. 2018
BibTeX:
@article{Zhang2018252,
  author = {Zhang, B. and Ding, X. and Werner, C. and Tan, K. and Zhang, B. and Jiang, M. and Zhao, J. and Xu, Y.},
  title = {Dynamic displacement monitoring of long-span bridges with a microwave radar interferometer},
  journal = {ISPRS Journal of Photogrammetry and Remote Sensing},
  publisher = {Elsevier B.V.},
  year = {2018},
  volume = {138},
  pages = {252-264},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042874489&doi=10.1016%2fj.isprsjprs.2018.02.020&partnerID=40&md5=88b9677635cc9fc606fc594128414c3b},
  doi = {10.1016/j.isprsjprs.2018.02.020}
}
Zheng D, Van Der Velde R, Wen J, Wang X, Ferrazzoli P, Schwank M, Colliander A, Bindlish R and Su Z (2018), "Assessment of the SMAP Soil Emission Model and Soil Moisture Retrieval Algorithms for a Tibetan Desert Ecosystem", IEEE Transactions on Geoscience and Remote Sensing. Vol. 56(7), pp. 3786-3799. Institute of Electrical and Electronics Engineers Inc..
Abstract: The Soil Moisture Active Passive (SMAP) satellite mission launched in January 2015 provides worldwide soil moisture (SM) monitoring based on L-band brightness temperature (TBp) measurements at horizontal (TBH) and vertical (TBV) polarizations. This paper presents a performance assessment of SMAP soil emission model and SM retrieval algorithms for a Tibetan desert ecosystem. It is found that the SMAP emission model largely underestimates the SMAP measured TBH (≈ 15 K), and the TBV is underestimated during dry-down episodes. A cold bias is noted for the SMAP effective temperature due to underestimation of soil temperature, leading to the TB p underestimation (>5 K). The remaining TB H underestimation is found to be related to the surface roughness parameterization that underestimates its effect on modulating the T B p measurements. Further, the topography and uncertainty of soil information are found to have minor impacts on the TB p simulations. The SMAP baseline SM products produced by single-channel algorithm (SCA) using the TBV measurements capture the measured SM dynamics well, while an underestimation is noted for the dry-down periods because of TB V underestimation. The products based on the SCA with TBH measurements underestimate the SM due to underestimation of TB H, and the dual-channel algorithm overestimates the SM. After implementing a new surface roughness parameterization and improving the soil temperature and texture information, the deficiencies noted above in TBp simulation and SM retrieval are greatly resolved. This indicates that the SMAP SM retrievals can be enhanced by improving both surface roughness and adopted soil temperature and texture information for Tibetan desert ecosystem.
BibTeX:
@article{Zheng20183786,
  author = {Zheng, D. and Van Der Velde, R. and Wen, J. and Wang, X. and Ferrazzoli, P. and Schwank, M. and Colliander, A. and Bindlish, R. and Su, Z.},
  title = {Assessment of the SMAP Soil Emission Model and Soil Moisture Retrieval Algorithms for a Tibetan Desert Ecosystem},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2018},
  volume = {56},
  number = {7},
  pages = {3786-3799},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044378015&doi=10.1109%2fTGRS.2018.2811318&partnerID=40&md5=9d216eab367bc60bb1b05b7dbf44c6f1},
  doi = {10.1109/TGRS.2018.2811318}
}
Zheng D, Wang X, van der Velde R, Ferrazzoli P, Wen J, Wang Z, Schwank M, Colliander A, Bindlish R and Su Z (2018), "Impact of surface roughness, vegetation opacity and soil permittivity on L-band microwave emission and soil moisture retrieval in the third pole environment", Remote Sensing of Environment. Vol. 209, pp. 633-647. Elsevier Inc..
Abstract: The brightness temperature (TBp) observed by the Soil Moisture Active Passive (SMAP) satellite mission is significantly affected by the soil permittivity (εs), surface roughness and vegetation opacity (τp). This study assesses the impact of these factors on simulating the SMAP horizontally (p = H) and vertically (p = V) polarized TBp measurements and retrieving the liquid soil water content (θliq) for both frozen and thawed soils in the typical Tibetan desert and meadow ecosystems. For this investigation, the zero-order approximation of the radiative transfer equations, i.e., τ-ω emission model, is configured with surface roughness and τp parameterizations adopted by current SMAP soil moisture retrieval algorithms, and the εs is computed with the four-phase dielectric mixing model that is applicable for both frozen and thawed soils. For the Tibetan desert site, the τ-ω emission model with above configurations underestimates year-round the SMAP TBH measurements (bias &gt; 20 K), while TBV are underestimated during the cold season. Implementation of a new surface roughness parameterization reduces the TBH underestimation, and the improved TBp simulations lead to better θliq retrievals produced by the single channel algorithm (SCA) using the TBV as well as TBH measurements. The remaining TBH and TBV underestimations are removed by further adopting a new εs parameterization. For the Tibetan meadow site, the τ-ω emission model overestimates both TBH and TBV during the warm season and underestimates TBH during the cold season when the vegetation is sparse. Implementation of the new surface roughness parameterization reduces the TBH underestimation, and further the TBp overestimation is mitigated by adopting a new τp parameterization derived from a discrete radiative transfer model previously developed and tested for the same site. The in-situ measured θliq dynamics are better captured by corresponding retrievals for both frozen and thawed soils with implementation of the new surface roughness and τp parameterizations, which reduces the unbiased RMSEs by more than 40%. The parameterizations developed in this study are useful to provide consistent and reasonable TBp simulations and θliq retrievals over the Tibetan Plateau for both frozen and thawed soils based on both SMAP TBH and TBV measurements. 2018 Elsevier Inc.
BibTeX:
@article{Zheng2018633,
  author = {Zheng, D. and Wang, X. and van der Velde, R. and Ferrazzoli, P. and Wen, J. and Wang, Z. and Schwank, M. and Colliander, A. and Bindlish, R. and Su, Z.},
  title = {Impact of surface roughness, vegetation opacity and soil permittivity on L-band microwave emission and soil moisture retrieval in the third pole environment},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2018},
  volume = {209},
  pages = {633-647},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043391931&doi=10.1016%2fj.rse.2018.03.011&partnerID=40&md5=ceeb8f9298b8b76eb36572c4789b56e5},
  doi = {10.1016/j.rse.2018.03.011}
}
Agarwal V, Bolch T, Syed T, Pieczonka T, Strozzi T and Nagaich R (2017), "Area and mass changes of Siachen Glacier (East Karakoram)", Journal of Glaciology. Vol. 63(237), pp. 148-163. Cambridge University Press.
Abstract: Here, we present a comprehensive assessment of Siachen Glacier (East Karakoram), in terms of its area and elevation change, velocity variations and mass budget, utilizing different satellite datasets including Landsat, Hexagon, Cartosat-I, Shuttle Radar Topography Mission, Envisat Advanced Synthetic Aperture Radar and Japanese Advanced Land Observing Satellite Phased Array-type L-band SAR. The total areal extent of Siachen Glacier did not change significantly between 1980 and 2014; however the exposed-ice area decreased during that period. The terminus of the glacier has experienced substantial downwasting (on average 30 m) over the period of 1999-2007, followed by a retreat of the transition between exposed and debris-covered ice by a distance of 1.3 km during the short span 2007-14. The spatial patterns of the elevation difference and velocity are heterogeneous over the large areal extent of Siachen Glacier. The average velocity of the entire glacier, as computed between 11 December 2008 and 26 January 2009, was 12.3 ± 0.4 cm d-1, while those estimated separately for the accumulation and ablation regions were 9.7 ± 0.4 cm d-1 and 20.4 ± 0.4 cm d-1, respectively. The mass budget of Siachen Glacier is estimated to be -0.03 ± 0.21 m w.e. a-1 for the period of 1999-2007. The Author(s) 2016.
BibTeX:
@article{Agarwal2017148,
  author = {Agarwal, V. and Bolch, T. and Syed, T.H. and Pieczonka, T. and Strozzi, T. and Nagaich, R.},
  title = {Area and mass changes of Siachen Glacier (East Karakoram)},
  journal = {Journal of Glaciology},
  publisher = {Cambridge University Press},
  year = {2017},
  volume = {63},
  number = {237},
  pages = {148-163},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009971505&doi=10.1017%2fjog.2016.127&partnerID=40&md5=dc940a44b267aa596a237d8b776c0c44},
  doi = {10.1017/jog.2016.127}
}
Cartus O, Santoro M, Wegmüller U and Rommen B (2017), "Estimating total aboveground, stem and branch biomass using multi-frequency SAR", In 2017 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images, MultiTemp 2017. Institute of Electrical and Electronics Engineers Inc..
Abstract: We have investigated the retrieval of total aboveground, stem and branch biomass using multi-temporal SAR data acquired at C-, L-, and P-band by Radarsat-2, ERS-2, ALOS PALSAR, and SETHI for a forest site in Sweden. A semi-empirical model was used to model C- and L-band backscatter as function of total aboveground, stem and branch biomass; a linear regression model was used for P-band. Calibrated with the aid of inventory plots, the models were used to estimate total aboveground, stem, and branch biomass for each individual scene in the multi-temporal and multi-frequency stack of observations. Individual estimates were then combined using weights reflecting each scenes' sensitivity to the biomass component in question. At the plot scale, the retrieval errors were 37, 40, and 33 % for total aboveground, stem, and branch biomass in terms of the relative RMSE; the error further reduced to 33, 38, and 27 % when calibrating models per species. We find that i) the retrieval of total aboveground, stem and branch biomass benefits from the availability of multi-temporal/-frequency data as the lowest retrieval errors with the best single image (P-band) were about 6 to 8 % higher, ii) there is no benefit in estimating total aboveground biomass via independent estimates of stem and branch biomass, iii) consideration of species specific differences associated with different allocations of biomass to stems and branches allows for improving the retrieval.
BibTeX:
@conference{Cartus2017,
  author = {Cartus, O. and Santoro, M. and Wegmüller, U. and Rommen, B.},
  title = {Estimating total aboveground, stem and branch biomass using multi-frequency SAR},
  booktitle = {2017 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images, MultiTemp 2017},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032378778&doi=10.1109%2fMulti-Temp.2017.8035231&partnerID=40&md5=93a79c696d4669b6779fd0729e744ae5},
  doi = {10.1109/Multi-Temp.2017.8035231}
}
Frey O, Werner C, Caduff R and Wiesmann A (2017), "Inversion of SNOW structure parameters from time series of tomographic measurements with SnowScat", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2017-July, pp. 2472-2475. Institute of Electrical and Electronics Engineers Inc..
Abstract: SnowScat is a terrestrial stepped-frequency continuous-wave (SFCW) scatterometer which supports fully-polarimetric measurements within a frequency band from 9.2 to 17.8 GHz. Recently, the hardware has been upgraded by adding a tomographic profiling mode. This tomographic approach allows to retrieve high-resolution information about a snowpack via observables, such as radar backscatter, co-polar phase difference, interferometric phase and coherence. Since the tomographic imaging itself is also affected by the refraction occurring at the air-snow interface and within the snowpack the two problems, 1) the production of well-focused and correctly located tomographic profiles, and 2) the retrieval of snow structure parameters are inherently linked. In this contribution, a tomographic inversion scheme to retrieve the refractive index of snow through an autofocus approach is presented. The current autofocus-based retrieval relies on using an aluminium sphere of a test target deployed in the scene. The refractive indices and accompanying snow density measurements obtained at four dates during a cold period in January during the ESA SnowLab 2016/2017 campaign are compared to an empirical model by Matzler and Wiesmann that describes the relation between snow density and the real part of the relative permittivity for dry snow.
BibTeX:
@conference{Frey20172472,
  author = {Frey, O. and Werner, C.L. and Caduff, R. and Wiesmann, A.},
  title = {Inversion of SNOW structure parameters from time series of tomographic measurements with SnowScat},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {2017-July},
  pages = {2472-2475},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041826573&doi=10.1109%2fIGARSS.2017.8127494&partnerID=40&md5=74f614ab9a0a4079a8b1a7a39a672fed},
  doi = {10.1109/IGARSS.2017.8127494}
}
Giordan D, Manconi A, Remondino F and Nex F (2017), "Use of unmanned aerial vehicles in monitoring application and management of natural hazards", Geomatics, Natural Hazards and Risk. Vol. 8(1), pp. 1-4. Taylor and Francis Ltd..
Abstract: The recent development of unmanned aerial vehicles (UAVs) has been increasing the number of technical solutions that can be used to monitor and map the effects of natural hazards. UAVs are generally cheaper and more versatile than traditional remote-sensing techniques, and they can be therefore considered as a good alternative for the acquisition of imagery and other physical parameters before, during and after a natural hazard event. This is an important added value especially for investigations over small areas (few km2). In the special issue ‘The use of Unmanned Aerial Vehicles in monitoring application and management of natural hazards’, we collected a number of case studies, aiming at providing a range of applications of monitoring and management of natural hazards assessed through the use of UAVs. 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Giordan20171,
  author = {Giordan, D. and Manconi, A. and Remondino, F. and Nex, F.},
  title = {Use of unmanned aerial vehicles in monitoring application and management of natural hazards},
  journal = {Geomatics, Natural Hazards and Risk},
  publisher = {Taylor and Francis Ltd.},
  year = {2017},
  volume = {8},
  number = {1},
  pages = {1-4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018381426&doi=10.1080%2f19475705.2017.1315619&partnerID=40&md5=ed9265dc7af78cd3c2af58136730d999},
  doi = {10.1080/19475705.2017.1315619}
}
Hocke K, Navas-Guzmán F, Moreira L, Bernet L and Matzler C (2017), "Diurnal cycle in atmospheric water over Switzerland", Remote Sensing. Vol. 9(9) MDPI AG.
Abstract: Abstract: The TROpospheric WAter RAdiometer (TROWARA) is a ground-based microwave radiometer with an additional infrared channel observing atmospheric water parameters in Bern, Switzerland. TROWARA measures with nearly all-weather capability during day- and nighttime with a high temporal resolution (about 10 s). Using the almost complete data set from 2004 to 2016, we derive and discuss the diurnal cycles in cloud fraction (CF), integrated liquid water (ILW) and integrated water vapour (IWV) for different seasons and the annual mean. The amplitude of the mean diurnal cycle in IWV is 0.41 kg/m2. The sub-daily minimum of IWV is at 10:00 LT while the maximum of IWV occurs at 19:00 LT. The relative amplitudes of the diurnal cycle in ILW are up to 25% in October, November and January, which is possibly related to a breaking up of the cloud layer at 10:00 LT. The minimum of ILW occurs at 12:00 LT, which is due to cloud solar absorption. In case of cloud fraction of liquid water clouds, maximal values of +10% are reached at 07:00 LT and then a decrease starts towards the minimum of -10%, which is reached at 16:00 LT in autumn. This breakup of cloud layers in the late morning and early afternoon hours seems to be typical for the weather in Bern in autumn. Finally, the diurnal cycle in rain fraction is analysed, which shows an increase of a few percent in the late afternoon hours during summer. 2017 by the authors.
BibTeX:
@article{Hocke2017,
  author = {Hocke, K. and Navas-Guzmán, F. and Moreira, L. and Bernet, L. and Matzler, C.},
  title = {Diurnal cycle in atmospheric water over Switzerland},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {9},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029385311&doi=10.3390%2frs9090909&partnerID=40&md5=ede2969f2612c6dab013a3152fd703e0},
  doi = {10.3390/rs9090909}
}
Hocke K, Navas-Guzmán F, Moreira L, Bernet L and Matzler C (2017), "Oscillations in atmospheric water above Switzerland", Atmospheric Chemistry and Physics. Vol. 17(19), pp. 12121-12131. Copernicus GmbH.
Abstract: Cloud fraction (CF), integrated liquid water (ILW) and integrated water vapour (IWV) were continuously measured from 2004 to 2016 by the TROpospheric WAter RAdiometer (TROWARA) in Bern, Switzerland. There are indications for interannual variations of CF and ILW. A spectral analysis shows that IWV is dominated by an annual oscillation, leading to an IWV maximum of 24kg m-2 in July to August and a minimum of 8kg m-2 in February. The seasonal behaviour of CF and ILW is composed by both the annual and the semiannual oscillation. However, the annual oscillation of CF has a maximum in December while the annual oscillation of ILW has a maximum in July. The semiannual oscillations of CF and ILW are strong from 2010 to 2014. The normalized power spectra of ILW and CF show statistically significant spectral components with periods of 76, 85, 97 and 150 days. We find a similarity between the power spectra of ILW and CF with those of zonal wind at 830hPa (1.5km) above Bern. Particularly, the occurrence of higher harmonics in the CF and ILW spectra is possibly forced by the behaviour of the lower-tropospheric wind. The mean amplitude spectra of CF, ILW and IWV show increased short-term variability on timescales less than 40 days from spring to fall. We find a weekly cycle of CF and ILW from June to September with increased values on Saturday, Sunday and Monday. 2017 Author(s).
BibTeX:
@article{Hocke201712121,
  author = {Hocke, K. and Navas-Guzmán, F. and Moreira, L. and Bernet, L. and Matzler, C.},
  title = {Oscillations in atmospheric water above Switzerland},
  journal = {Atmospheric Chemistry and Physics},
  publisher = {Copernicus GmbH},
  year = {2017},
  volume = {17},
  number = {19},
  pages = {12121-12131},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031316815&doi=10.5194%2facp-17-12121-2017&partnerID=40&md5=7f6c0ee771a9f1b6cecb46e8a7fcfafa},
  doi = {10.5194/acp-17-12121-2017}
}
Kerr Y, Mahmoodi A, Mialon A, Al Biltar A, Rodríguez-Fernández N, Richaume P, Cabot F, Wigneron J, Waldteufel P, Ferrazzoli P, Schwank M and Delwart S (2017), "Soil moisture retrieval algorithms: The SMOS case", Comprehensive Remote Sensing. Vol. 1-9, pp. 156-190. Elsevier.
Abstract: After the successful acquisition by a coarse L-band radiometer on board Skylab in the early seventies, the potential of L-band radiometry was made clear in spite of a strict limitation linked to minimum antenna dimensions required for appropriate spatial resolution. More than 20 years later new antenna concepts emerged to mitigate this physical constraint. The first to emerge, in 1997, and to become a reality, was the Soil Moisture and Ocean Salinity (SMOS) mission (Kerr, 1997, Kerr, 1998). It is European Space Agency’s (ESA’s) second Earth Explorer Opportunity mission (Kerr et al., 2001), launched in November 2009. It is a joint program between ESA, CNES (Centre National d’Etudes Spatiales), and CDTI (Centro para el Desarrollo Tecnologico Industrial). SMOS carries a single payload, an L-band 2D interferometric radiometer in the 1400-1427 MHz protected band. This wavelength penetrates well through the atmosphere, and hence, the instrument probes the Earth surface emissivity from space. Surface emissivity can be related to the moisture content in the first few centimeters of soil, and after some surface roughness and temperature corrections, to the sea surface salinity over ocean. Soil moisture retrieval from SMOS observations with a required accuracy of 0.04 m3/m3 is challenging and involves many steps. The retrieval algorithms are developed and implemented in the ground segment, which processes level 1 and level 2 data. Level 1 consists mainly of directional brightness temperatures, while level 2 consists of geophysical products in swath mode, i.e., for successive imaging snapshots acquired by the sensor during a half orbit from pole to pole. Level 3 consists in composites of brightness temperatures, or geophysical products over time and space, i.e., global maps over given temporal periods from 1 day to 1 month. In this context, a group of institutes prepared the soil moisture and ocean salinity Algorithm Theoretical Basis Documents (ATBD), used to in operational soil moisture and sea salinity retrieval algorithms (Kerr et al., 2010a). The principle of the level 2 soil moisture retrieval algorithm is based on an iterative approach, which aims at minimizing a cost function. The main component of the cost function is given by the sum of the squared weighted differences between measured and modeled brightness temperature (TB) at horizontal and vertical polarizations, for a variety of incidence angles. The algorithm finds the best set of parameters, e.g., soil moisture (SM) and vegetation characteristics, which drive the TB model and minimizes the cost function. From this algorithm, a more sophisticated one was developed to take into account multiorbit retrievals (i.e., level 3). Subsequently, after several years of data acquisition and algorithm improvements, a neural network approach was developed so as to be able to infer soil moisture fields in near-real time. In parallel, several simplified algorithms were tested, the goal being to achieve a seamless transition with other sensors, along with other studies targeted on specific targets such as dense forests, organic rich soils, or frozen and snow-covered grounds. Finally, it may be noted that most of these approaches deliver not only the surface soil moisture but also other quantities of interest such as vegetation optical depth, surface roughness, and surface dielectric constant. The goal of this article is to give an overview of these different approaches and corresponding results and adequate references for those wishing to go further. Sea surface salinity is not covered in this article, while the focus is SMOS data. 2018 Elsevier Inc. All rights reserved.
BibTeX:
@book{Kerr2017156,
  author = {Kerr, Y.H. and Mahmoodi, A. and Mialon, A. and Al Biltar, A. and Rodríguez-Fernández, N. and Richaume, P. and Cabot, F. and Wigneron, J.P. and Waldteufel, P. and Ferrazzoli, P. and Schwank, M. and Delwart, S.},
  title = {Soil moisture retrieval algorithms: The SMOS case},
  journal = {Comprehensive Remote Sensing},
  publisher = {Elsevier},
  year = {2017},
  volume = {1-9},
  pages = {156-190},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068151872&doi=10.1016%2fB978-0-12-409548-9.10355-0&partnerID=40&md5=8c67df4f9d61ebc2650b0dd95610d904},
  doi = {10.1016/B978-0-12-409548-9.10355-0}
}
Lamarche C, Santoro M, Bontemps S, d'Andrimont R, Radoux J, Giustarini L, Brockmann C, Wevers J, Defourny P and Arino O (2017), "Compilation and validation of sar and optical data products for a complete and global map of inland/ocean water tailored to the climate modeling community", Remote Sensing. Vol. 9(1) MDPI AG.
Abstract: Accurate maps of surface water extent are of paramount importance for water management, satellite data processing and climate modeling. Several maps of water bodies based on remote sensing data have been released during the last decade. Nonetheless, none has a truly (90°N/90°S) global coverage while being thoroughly validated. This paper describes a global, spatially-complete (void-free) and accurate mask of inland/ocean water for the 2000-2012 period, built in the framework of the European Space Agency (ESA) Climate Change Initiative (CCI). This map results from the synergistic combination of multiple individual SAR and optical water body and auxiliary datasets. A key aspect of this work is the original and rigorous stratified random sampling designed for the quality assessment of binary classifications where one class is marginally distributed. Input and consolidated products were assessed qualitatively and quantitatively against a reference validation database of 2110 samples spread throughout the globe. Using all samples, overall accuracy was always very high among all products, between 98% and 100%. The CCI global map of open water bodies provided the best water class representation (F-score of 89%) compared to its constitutive inputs. When focusing on the challenging areas for water bodies' mapping, such as shorelines, lakes and river banks, all products yielded substantially lower accuracy figures with overall accuracies ranging between 74% and 89%. The inland water area of the CCI global map of open water bodies was estimated to be 3.17 million km2 ± 0.24 million km2. The dataset is freely available through the ESA CCI Land Cover viewer. 2017 by the authors; licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Lamarche2017,
  author = {Lamarche, C. and Santoro, M. and Bontemps, S. and d'Andrimont, R. and Radoux, J. and Giustarini, L. and Brockmann, C. and Wevers, J. and Defourny, P. and Arino, O.},
  title = {Compilation and validation of sar and optical data products for a complete and global map of inland/ocean water tailored to the climate modeling community},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010644464&doi=10.3390%2frs9010036&partnerID=40&md5=20448e3b47010ee7d4b319054adecb08},
  doi = {10.3390/rs9010036}
}
Lemmetyinen J, Rautiainen K, Luojus K, Rott H, Nagler T, Parrella G, Hajnsek I, Derksen C, Macelloni G, Brogioni M, Wiesmann A, Matzler C and Kern M (2017), "Future mission concepts for measuring snow mass", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2017-July, pp. 1370-1371. Institute of Electrical and Electronics Engineers Inc..
Abstract: There is a long-stranding need of reliable space-borne observations on snow mass. Current satellite sensors and data products are largely unable to meet requirements presented in particular by numerical prediction and watershed management. Consequently, several concept studies have been initiated to address these specific needs, outlining possibilities for future space sensors focusing on retrieval of snow mass and other characteristics of the terrestrial cryosphere. The results of these of-going mission concept studies are presented and discussed. Several possible sensor options are presented, which would address diverse needs on either hemispheric or regional scales.
BibTeX:
@conference{Lemmetyinen20171370,
  author = {Lemmetyinen, J. and Rautiainen, K. and Luojus, K. and Rott, H. and Nagler, T. and Parrella, G. and Hajnsek, I. and Derksen, C. and Macelloni, G. and Brogioni, M. and Wiesmann, A. and Matzler, C. and Kern, M.},
  title = {Future mission concepts for measuring snow mass},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {2017-July},
  pages = {1370-1371},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041849585&doi=10.1109%2fIGARSS.2017.8127217&partnerID=40&md5=ea03cd7990d402018a4a05e502fac525},
  doi = {10.1109/IGARSS.2017.8127217}
}
Li W, Ciais P, Peng S, Yue C, Wang Y, Thurner M, Saatchi S, Arneth A, Avitabile V, Carvalhais N, Harper A, Kato E, Koven C, Liu Y, Nabel J, Pan Y, Pongratz J, Poulter B, Pugh T, Santoro M, Sitch S, Stocker B, Viovy N, Wiltshire A, Yousefpour R and Zaehle S (2017), "Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations", Biogeosciences. Vol. 14(22), pp. 5053-5067. Copernicus GmbH.
Abstract: The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions and for ecosystem processes affected by LULCC. One drawback of LULCC emissions from DGVMs, however, is lack of observation constraint. Here, we propose a new method of using satellite- and inventory-based biomass observations to constrain historical cumulative LULCC emissions (ELUCc) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and ELUCc. This method is applicable on the global and regional scale. The original DGVM estimates of ELUCc range from 94 to 273PgC during 1901-2012. After constraining by current biomass observations, we derive a best estimate of 155±50PgC (1σ Gaussian error). The constrained LULCC emissions are higher than prior DGVM values in tropical regions but significantly lower in North America. Our emergent constraint approach independently verifies the median model estimate by biomass observations, giving support to the use of this estimate in carbon budget assessments. The uncertainty in the constrained ELUCc is still relatively large because of the uncertainty in the biomass observations, and thus reduced uncertainty in addition to increased accuracy in biomass observations in the future will help improve the constraint. This constraint method can also be applied to evaluate the impact of land-based mitigation activities.
BibTeX:
@article{Li20175053,
  author = {Li, W. and Ciais, P. and Peng, S. and Yue, C. and Wang, Y. and Thurner, M. and Saatchi, S.S. and Arneth, A. and Avitabile, V. and Carvalhais, N. and Harper, A.B. and Kato, E. and Koven, C. and Liu, Y.Y. and Nabel, J.E.M.S. and Pan, Y. and Pongratz, J. and Poulter, B. and Pugh, T.A.M. and Santoro, M. and Sitch, S. and Stocker, B.D. and Viovy, N. and Wiltshire, A. and Yousefpour, R. and Zaehle, S.},
  title = {Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations},
  journal = {Biogeosciences},
  publisher = {Copernicus GmbH},
  year = {2017},
  volume = {14},
  number = {22},
  pages = {5053-5067},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034055468&doi=10.5194%2fbg-14-5053-2017&partnerID=40&md5=2c1570087902ded73088c5f7a451a467},
  doi = {10.5194/bg-14-5053-2017}
}
da Lio C, Strozzi T, Teatini P and Tosi L (2017), "Computing the relative land subsidence at Venice, Italy, over the last fifty years", In Proceedings - 22nd International Congress on Modelling and Simulation, MODSIM 2017. , pp. 999-1005. Modelling and Simulation Society of Australia and New Zealand Inc. (MSSANZ).
Abstract: Land subsidence causes various damages to the infrastructures and cultural heritage in many cities worldwide. Urban flooding is one of the main consequences of land subsidence in coastal cities, where it is exacerbated by sea-level rise accompanying global climate change, but also in inland metropolitan areas such as Mexico City, where subsidence zones are increasingly flooded following intense rainstorms. The subsidence of Venice, one of the most beautiful and famous cities in the world, is well known not for the magnitude of subsidence but because subsidence has seriously compromised the heritage and the safety of the city in relation to its small elevation above the sea. The storm that flooded the historical center of Venice on November 4, 1966 dramatically revealed its fragility with respect to land subsidence and sea-level rise, or the Relative Land Subsidence (RLS), i.e. land movement with respect to sea-level changes. That event signaled the beginning of a systematic monitoring of the loss in elevation of the ground surface of Venice with respect to the mean level of the Northern Adriatic (NA) Sea. Tide gauge measurements, available from the beginning of the last century, have been supplied historically by levelling and more recently by Synthetic Aperture Radar (SAR)-based Interferometry. On the occasion of the 50th anniversary of the 1966 flood event, we quantify the RLS experienced by the city over these last five decades with a detail never achieved before. The computation of the loss of elevation has been obtained by processing and superposing the results of levelling surveys carried out in 1961, 1969, 1973, and 1993, together with the results of Interferometric processing of SAR images acquired from satellites: 1993 to 2002 by ERS-1/2, 2003 and 2010 by ENVISAT, 2008 to 2013 by TerraSAR-X, and 2012 to 2016 by COSMO-SkyMED. The records from the tide gauge in Trieste, which is a city on the coast of the NA Sea close to the Alps and known to be stable, are used to evaluate the sea-level rise over the targeted time interval. The mean land velocity (v) for each analyzed period has been obtained by interpolating the original measurements using the Kriging method on a same regular 50-m grid covering the entire city. Then, cumulative land subsidence (LStot)) from 1966 to 2016 has been simulated in a GIS environment by summing the partial land subsidence over the various periods covered by the levelling and SAR surveys. The results point out that in the Venice historical center between 1966 and 2016: • Land subsidence rate has been more variable in space but less variable over time than the changes of the NA mean sea level; • average subsidence has amounted to 0.8 mm/yr and the average NA msl rise to 1.9 mm/yr; • minimum and maximum cumulative subsidence has totalled 8 mm and 93 mm, respectively; and • maximum loss of elevation with respect to the NA msl (i.e. RLS) has been 190 mm. RLS has produced a tangible effect on the Venice historical center revealed by the continuous increase in frequency of the flooding events, locally called "acqua alta". In the next years, any further loss of elevation with respect to the mean sea level, even a few mm, will threaten the city’s survival with severe social and environmental impacts. Considering the present average land subsidence of Venice and sea level rise of the NA (i.e. both about 1.2 mm/yr), an additional loss of elevation of about 190 mm will likely occur by 2100. Actually, according to conservative and pessimistic IPCC scenarios, the sea-level accompanying global climate change is expected to rise from 32 to 56 cm. Therefore, the outcomes from this study should be properly taken in account for the planning of effective interventions for the mitigation of climate changes to maintain the historical center of this unique city. 2017 Proceedings - 22nd International Congress on Modelling and Simulation, MODSIM 2017. All rights reserved.
BibTeX:
@conference{daLio2017999,
  author = {da Lio, C. and Strozzi, T. and Teatini, P. and Tosi, L.},
  title = {Computing the relative land subsidence at Venice, Italy, over the last fifty years},
  booktitle = {Proceedings - 22nd International Congress on Modelling and Simulation, MODSIM 2017},
  publisher = {Modelling and Simulation Society of Australia and New Zealand Inc. (MSSANZ)},
  year = {2017},
  pages = {999-1005},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080943446&partnerID=40&md5=710592c4d6969a107b13e9051aaedb56}
}
Manconi A, Glueer F and Loew S (2017), "Spatial and temporal evolution of rock fall activity on a failing slope", In ISRM Progressive Rock Failure Conference, PRF 2017. Vol. 2017-June International Society for Rock Mechanics.
Abstract: The main goal of this study is to describe the spatial and temporal evolution of rock fall phenomena triggered by rapid slope deformation. To this end, we combine low cost seismic sensors and image processing to study a large instability adjacent to the Great Aletsch glacier in the Swiss Alps, i.e. the Moosfluh slope, which is undergoing an acceleration phase since the late summer 2016. With this analysis, we aim at a better understanding of the relationship between the kinematic behavior of rock slope instabilities and progressive rock mass damage, which may lead to catastrophic failure. 2017 Brno University of Technology. All Rights Reserved.
BibTeX:
@conference{Manconi2017,
  author = {Manconi, A. and Glueer, F. and Loew, S.},
  title = {Spatial and temporal evolution of rock fall activity on a failing slope},
  booktitle = {ISRM Progressive Rock Failure Conference, PRF 2017},
  publisher = {International Society for Rock Mechanics},
  year = {2017},
  volume = {2017-June},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048554487&partnerID=40&md5=4ae95567574e4051703e91f3d11a4ad8}
}
Mattia F, Balenzano A, Satalino G, Lovergine F, Loew A, Peng J, Wegmüller U, Santoro M, Cartus O, Dabrowska-Zielinska K, Musial J, Davidson M, Yueh S, Kim S, Das N, Colliander A, Johnson J, Ouellette J, Walker J, Wu X, McNairn H, Merzouki A, Powers J, Caldwell T, Entekhabi D, Cosh M and Jackson T (2017), "Sentinel-1 high resolution soil moisture", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2017-July, pp. 5533-5536. Institute of Electrical and Electronics Engineers Inc..
Abstract: The systematic retrieval of near surface soil moisture (SSM) fields at high resolution (e.g., 0.1-1.0 km) is a challenging task that requires the exploitation of new retrieval algorithms and SAR data with advanced observational capabilities (in terms of spatial/temporal resolution, radiometric accuracy, very large swath, long-term continuity and rapid data dissemination). The launch of the Sentinel-1 (S-1) constellation provides these capabilities and calls for the development and validation of pre-operational SSM products at high resolution. The objective of this paper is to present and initially assess a SSM retrieval algorithm developed in view of S-1 data exploitation. The activity is supported by a large scientific community engaged in fostering a more effective interaction between researchers working in the field of high and low resolution SSM retrieval.
BibTeX:
@conference{Mattia20175533,
  author = {Mattia, F. and Balenzano, A. and Satalino, G. and Lovergine, F. and Loew, A. and Peng, J. and Wegmüller, U. and Santoro, M. and Cartus, O. and Dabrowska-Zielinska, K. and Musial, J. and Davidson, M.W.J. and Yueh, S. and Kim, S. and Das, N. and Colliander, A. and Johnson, J. and Ouellette, J. and Walker, J. and Wu, X. and McNairn, H. and Merzouki, A. and Powers, J. and Caldwell, T. and Entekhabi, D. and Cosh, M. and Jackson, T.},
  title = {Sentinel-1 high resolution soil moisture},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {2017-July},
  pages = {5533-5536},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041865566&doi=10.1109%2fIGARSS.2017.8128257&partnerID=40&md5=5c7b7cca90a917b2f9c631fd64b76aba},
  doi = {10.1109/IGARSS.2017.8128257}
}
Mendez Dominguez E, Magnard C, Frioud M, Small D and Meier E (2017), "Adaptive Pulse Compression for Range Focusing in SAR Imagery", IEEE Transactions on Geoscience and Remote Sensing. Vol. 55(4), pp. 2262-2275. Institute of Electrical and Electronics Engineers Inc..
Abstract: Synthetic aperture radar (SAR) images are focused via range and azimuth compression. Typically, a matched filter is used for range compression. However, its inherent operation introduces target masking due to sidelobes, reducing the recognition and interpretability of the underlying targets. To optimize the focusing quality, adaptive pulse compression (APC) can be applied. In this paper, APC is assessed for range processing in SAR image focusing. The performance of the method is evaluated with airborne SAR imagery and compared with those of traditional schemes. We show that by applying APC under single-channel interferometric and stepped frequency scenarios, the quality of the SAR images, the corresponding phase maps, and interferometric coherence images can be significantly improved, and that APC provides both better amplitude and phase estimates of the range profiles. APC is shown to preserve the characteristics of the azimuth signals and can be applied without restricting the azimuth compression scheme.
BibTeX:
@article{MendezDominguez20172262,
  author = {Mendez Dominguez, E. and Magnard, C. and Frioud, M. and Small, D. and Meier, E.},
  title = {Adaptive Pulse Compression for Range Focusing in SAR Imagery},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {55},
  number = {4},
  pages = {2262-2275},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009840453&doi=10.1109%2fTGRS.2016.2641041&partnerID=40&md5=59378c56c2924c5d1d45db2d8a4deb6f},
  doi = {10.1109/TGRS.2016.2641041}
}
Moro M, Saroli M, Stramondo S, Bignami C, Albano M, Falcucci E, Gori S, Doglioni C, Polcari M, Tallini M, Macerola L, Novali F, Costantini M, Malvarosa F and Wegmüller U (2017), "New insights into earthquake precursors from InSAR", Scientific Reports. Vol. 7(1) Nature Publishing Group.
Abstract: We measured ground displacements before and after the 2009 L'Aquila earthquake using multi-temporal InSAR techniques to identify seismic precursor signals. We estimated the ground deformation and its temporal evolution by exploiting a large dataset of SAR imagery that spans seventy-two months before and sixteen months after the mainshock. These satellite data show that up to 15 mm of subsidence occurred beginning three years before the mainshock. This deformation occurred within two Quaternary basins that are located close to the epicentral area and are filled with sediments hosting multi-layer aquifers. After the earthquake, the same basins experienced up to 12 mm of uplift over approximately nine months. Before the earthquake, the rocks at depth dilated, and fractures opened. Consequently, fluids migrated into the dilated volume, thereby lowering the groundwater table in the carbonate hydrostructures and in the hydrologically connected multi-layer aquifers within the basins. This process caused the elastic consolidation of the fine-grained sediments within the basins, resulting in the detected subsidence. After the earthquake, the fractures closed, and the deep fluids were squeezed out. The pre-seismic ground displacements were then recovered because the groundwater table rose and natural recharge of the shallow multi-layer aquifers occurred, which caused the observed uplift. 2017 The Author(s).
BibTeX:
@article{Moro2017,
  author = {Moro, M. and Saroli, M. and Stramondo, S. and Bignami, C. and Albano, M. and Falcucci, E. and Gori, S. and Doglioni, C. and Polcari, M. and Tallini, M. and Macerola, L. and Novali, F. and Costantini, M. and Malvarosa, F. and Wegmüller, U.},
  title = {New insights into earthquake precursors from InSAR},
  journal = {Scientific Reports},
  publisher = {Nature Publishing Group},
  year = {2017},
  volume = {7},
  number = {1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029649721&doi=10.1038%2fs41598-017-12058-3&partnerID=40&md5=07801712c8bc2db4f975e46fb523b2f9},
  doi = {10.1038/s41598-017-12058-3}
}
Naderpour R, Schwank M and Matzler C (2017), "Davos-laret remote sensing field laboratory: 2016/2017 Winter season L-band measurements data-processing and analysis", Remote Sensing. Vol. 9(11) MDPI AG.
Abstract: The L-band radiometry data and in-situ ground and snow measurements performed during the 2016/2017 winter campaign at the Davos-Laret remote sensing field laboratory are presented and discussed. An improved version of the procedure for the computation of L-band brightness temperatures from ELBARA radiometer raw data is introduced. This procedure includes a thorough explanation of the calibration and filtering including a refined radio frequency interference (RFI) mitigation approach. This new mitigation approach not only performs better than conventional "normality" tests (kurtosis and skewness) but also allows for the quantification of measurement uncertainty introduced by non-thermal noise contributions. The brightness temperatures of natural snow covered areas and areas with a reflector beneath the snow are simulated for varying amounts of snow liquid water content distributed across the snow profile. Both measured and simulated brightness temperatures emanating from natural snow covered areas and areas with a reflector beneath the snow reveal noticeable sensitivity with respect to snow liquid water. This indicates the possibility of estimating snow liquid water using L-band radiometry. It is also shown that distinct daily increases in brightness temperatures measured over the areas with the reflector placed on the ground indicate the onset of the snow melting season, also known as "early-spring snow". 2017 by the authors.
BibTeX:
@article{Naderpour2017,
  author = {Naderpour, R. and Schwank, M. and Matzler, C.},
  title = {Davos-laret remote sensing field laboratory: 2016/2017 Winter season L-band measurements data-processing and analysis},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {11},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034768764&doi=10.3390%2frs9111185&partnerID=40&md5=e4eb313a2662e85461cc3d4776f0a19d},
  doi = {10.3390/rs9111185}
}
Naderpour R, Schwank M, Matzler C, Lemmetyinen J and Steffen K (2017), "Snow Density and Ground Permittivity Retrieved From L-Band Radiometry: A Retrieval Sensitivity Analysis", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 10(7), pp. 3148-3161. Institute of Electrical and Electronics Engineers.
Abstract: Aboveground dry snow influences the L-band ground-snow system emissivity as the result of impedance matching and refraction effects. Against this background, a retrieval scheme was proposed to estimate dry-snow density and ground permittivity from passive L-band measurements. In this study, the sensitivity of the recently proposed retrieval scheme with respect to surface roughness and snowpack density profile heterogeneities is investigated using synthetic brightness temperatures TBp. While the original retrieval algorithm proposed to use TBp(θ) at observation angles θ and both polarizations p = "H" and p = "V", the present analysis involves three polarization retrieval modes: "HV", "H", and "V" to identify the most robust one. The analyses based on synthetic TBp(θ) suggest the use of exclusively vertical polarization ("V" retrieval mode) in case of low "instrumental noise" of σTB &lt; 0.5 K, as it yields most accurate results in the presence of heterogeneities in profiles and imperfect parametrization of ground surface roughness. The applied retrieval scheme still yields accurate results even in the presence of "instrumental noise" (σTB ≥ 0.5 K) in retrieval mode "HV". Furthermore, it is shown that ground-permittivity retrievals are less affected than snow density retrievals by ground roughness variations or heterogeneities in snow density profiles. Altogether, our sensitivity investigations indicate the robustness of the retrieval scheme applied thereto with respect to snow density profile heterogeneities, which is expedient for its use with spaceborne radiometry data from, for example, "Soil Moisture and Ocean Salinity" or "Soil Moisture Active Passive" satellites.
BibTeX:
@article{Naderpour20173148,
  author = {Naderpour, R. and Schwank, M. and Matzler, C. and Lemmetyinen, J. and Steffen, K.},
  title = {Snow Density and Ground Permittivity Retrieved From L-Band Radiometry: A Retrieval Sensitivity Analysis},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2017},
  volume = {10},
  number = {7},
  pages = {3148-3161},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015677887&doi=10.1109%2fJSTARS.2017.2669336&partnerID=40&md5=630bf52b38a258722e0919224d4db133},
  doi = {10.1109/JSTARS.2017.2669336}
}
Paul F, Bolch T, Briggs K, Kaab A, McMillan M, McNabb R, Nagler T, Nuth C, Rastner P, Strozzi T and Wuite J (2017), "Error sources and guidelines for quality assessment of glacier area, elevation change, and velocity products derived from satellite data in the Glaciers_cci project", Remote Sensing of Environment. Vol. 203, pp. 256-275. Elsevier Inc..
Abstract: Satellite data provide a large range of information on glacier dynamics and changes. Results are often reported, provided and used without consideration of measurement accuracy (difference to a true value) and precision (variability of independent assessments). Whereas accuracy might be difficult to determine due to the limited availability of appropriate reference data and the complimentary nature of satellite measurements, precision can be obtained from a large range of measures with a variable effort for determination. This study provides a systematic overview on the factors influencing accuracy and precision of glacier area, elevation change (from altimetry and DEM differencing), and velocity products derived from satellite data, along with measures for calculating them. A tiered list of recommendations is provided (sorted for effort from Level 0 to 3) as a guide for analysts to apply what is possible given the datasets used and available to them. The more simple measures to describe product quality (Levels 0 and 1) can often easily be applied and should thus always be reported. Medium efforts (Level 2) require additional work but provide a more realistic assessment of product precision. Real accuracy assessment (Level 3) requires independent and coincidently acquired reference data with high accuracy. However, these are rarely available and their transformation into an unbiased source of information is challenging. This overview is based on the experiences and lessons learned in the ESA project Glaciers_cci rather than a review of the literature. 2017
BibTeX:
@article{Paul2017256,
  author = {Paul, F. and Bolch, T. and Briggs, K. and Kaab, A. and McMillan, M. and McNabb, R. and Nagler, T. and Nuth, C. and Rastner, P. and Strozzi, T. and Wuite, J.},
  title = {Error sources and guidelines for quality assessment of glacier area, elevation change, and velocity products derived from satellite data in the Glaciers_cci project},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2017},
  volume = {203},
  pages = {256-275},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029384858&doi=10.1016%2fj.rse.2017.08.038&partnerID=40&md5=f75d1041f062c917c43775f3f453914e},
  doi = {10.1016/j.rse.2017.08.038}
}
Paul F, Strozzi T, Schellenberger T and Kaab A (2017), "The 2015 surge of hispar glacier in the karakoram", Remote Sensing. Vol. 9(9) MDPI AG.
Abstract: The Karakoram mountain range iswell known for its numerous surge-type glaciers of which several have recently surged or are still doing so. Analysis of multi-temporal satellite images and digital elevation models have revealed impressive details about the related changes (e.g., in glacier length, surface elevation and flow velocities) and considerably expanded the database of known surge-type glaciers. One glacier that has so far only been reported as impacted by surging tributaries, rather than surging itself, is the 50 km long main trunk of Hispar Glacier in the Hunza catchment. We here present the evolution of flow velocities and surface features from its 2015/16 surge as revealed from a dense time series of SAR and optical images along with an analysis of historic satellite images. We observed maximum flow velocities of up to 14 m d-1 (5 km a-1) in spring 2015, sudden drops in summer velocities, a second increase in winter 2015/16 and a total advance of the surge front of about 6 km. During a few months the surge front velocity was much higher (about 90 m d-1) than the maximum flow velocity. We assume that one of its northern tributary glaciers, Yutmaru, initiated the surge at the end of summer 2014 and that the variability in flow velocities was driven by changes in the basal hydrologic regime (Alaska-type surge). We further provide evidence that Hispar Glacier has surged before (around 1960) over a distance of about 10 km so that it can also be regarded as a surge-type glacier. 2017 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Paul2017,
  author = {Paul, F. and Strozzi, T. and Schellenberger, T. and Kaab, A.},
  title = {The 2015 surge of hispar glacier in the karakoram},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {9},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029385560&doi=10.3390%2frs9090888&partnerID=40&md5=bc462034b0f58067c622c6bdc432dbf5},
  doi = {10.3390/rs9090888}
}
Rastner P, Strozzi T and Paul F (2017), "Fusion of multi-source satellite data and DEMs to create a new glacier inventory for Novaya Zemlya", Remote Sensing. Vol. 9(11) MDPI AG.
Abstract: Monitoring glacier changes in remote Arctic regions are strongly facilitated by satellite data. This is especially true for the Russian Arctic where recently increased optical and SAR satellite imagery (Landsat 8 OLI, Sentinel 1/2) and digital elevation models (TanDEM-X, ArcticDEM) are becoming available. These datasets offer new possibilities to create high-quality glacier inventories. Here, we present a new glacier inventory derived from a fusion of multi-source satellite data for Novaya Zemlya in the Russian Arctic. We mainly used Landsat 8 OLI data to automatically map glaciers with the band ratio method. Missing debris-covered glacier parts and misclassified lakes were manually corrected. Whereas perennial snow fields were a major obstacle in glacier identification, seasonal snow was identified and removed using Landsat 5 TM scenes from the year 1998. Drainage basins were derived semi-automatically using the ArcticDEM (gap-filled by the ASTER GDEM V2) and manually corrected using fringes from ALOS PALSAR. The new glacier inventory gives a glacierized area of 22,379 ± 246.2 km2 with 1474 glacier entities &gt; 0.05 km2. The region is dominated by large glaciers, as 909 glaciers &lt; 0.5 km2 (62% by number) cover only 156 ± 1.7 km2 or 0.7% of the area, whereas 49 glaciers &gt; 100 km2 (3.3% by number) cover 18,724 ± 205.9 km2 or 84%. In total, 41 glaciers are marine terminating covering an area of 16,063.7 ± 118.8 km2. The mean elevation is 596 m for all glaciers in the study region (528 m in the northern part, 641 in the southern part). South-east (north-west) facing glaciers cover &gt; 35% (20%) of the area. For the smaller glaciers in the southern part we calculated an area loss of 3.4% (-52.5 ± 3.1 km2) from 2001 to 2016. 2017 by the authors.
BibTeX:
@article{Rastner2017,
  author = {Rastner, P. and Strozzi, T. and Paul, F.},
  title = {Fusion of multi-source satellite data and DEMs to create a new glacier inventory for Novaya Zemlya},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {11},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029382655&doi=10.3390%2frs9111122&partnerID=40&md5=272fd6c85ee25f166655ecdebcb63191},
  doi = {10.3390/rs9111122}
}
Siddique M, Hajnsek I and Frey O (2017), "A case study on the use of differential SAR tomography for measuring deformation in layover areas in rugged alpine terrain", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2017-July, pp. 5850-5853. Institute of Electrical and Electronics Engineers Inc..
Abstract: Differential SAR tomography is a means to resolve layover of temporally coherent scatterers while simultaneously estimating their elevation and average deformation. In alpine regions, drastic height variations result in frequent layovers which are rejected during typical persistent scatterer interferometric (PSI) analyses. In this paper, we explore the potential of tomographic techniques to improve deformation sampling in an alpine region of interest relative to a PSI-based deformation assessment. The mitigation of the atmospheric phase contributions, as required for both tomography and PSI, is often more involved in alpine regions due to strong spatial variations of the local atmospheric conditions and propagation paths through the troposphere. We assume a linear multivariate dependence of atmospheric phase on the spatial location and height of the scatterers, estimate it using universal/regression kriging and subsequently incorporate it within the tomographic focusing. Experiments are performed on an interferometric stack comprising of 32 Cosmo-SkyMed strimap images acquired in the summers of 2008-2013 over Mattervalley in the Swiss Alps.
BibTeX:
@conference{Siddique20175850,
  author = {Siddique, M.A. and Hajnsek, I. and Frey, O.},
  title = {A case study on the use of differential SAR tomography for measuring deformation in layover areas in rugged alpine terrain},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {2017-July},
  pages = {5850-5853},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041819260&doi=10.1109%2fIGARSS.2017.8128339&partnerID=40&md5=0dac0f3cc4ac54157eb2bff17de5e2d1},
  doi = {10.1109/IGARSS.2017.8128339}
}
Strozzi T, Caduff R, Wegmüller U, Raetzo H and Hauser M (2017), "Widespread surface subsidence measured with satellite SAR interferometry in the Swiss alpine range associated with the construction of the Gotthard Base Tunnel", Remote Sensing of Environment. Vol. 190, pp. 1-12. Elsevier Inc..
Abstract: Drilling deep tunnels in alpine rocks might induce surface settlements of a few centimetres because of groundwater drainage and associated pore pressure reduction. Settlements of this order of magnitude are sufficient to pose a potential threat to the integrity of any large concrete structure such as arch dams located above the tunnel and an accurate survey of surface deformation before, during and after construction is of high importance. We present the spatial and temporal evolution of surface subsidence measured with satellite SAR interferometry associated with the construction of the 57 km long Gotthard Base Tunnel in Switzerland. Significant deformations of 1 to 12 mm/year were detected between 2003 and 2010 with ENVISAT ASAR data above the tunnel on villages and sparsely vegetated alpine slopes where no displacement was recorded between 1992 and 2000 with ERS-1/2 SAR data. Our results, available also for sectors where there is no information from any other surveying technique, are important not only to assess the hazard posed on any large concrete structure but also for the development and calibration of numerical models - to be employed to simulate the expected surface deformation before and during the construction works - and to study the effect of groundwater drainage on the dynamic of large deep-seated landslides. 2016 Elsevier Inc.
BibTeX:
@article{Strozzi20171,
  author = {Strozzi, T. and Caduff, R. and Wegmüller, U. and Raetzo, H. and Hauser, M.},
  title = {Widespread surface subsidence measured with satellite SAR interferometry in the Swiss alpine range associated with the construction of the Gotthard Base Tunnel},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2017},
  volume = {190},
  pages = {1-12},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006395750&doi=10.1016%2fj.rse.2016.12.007&partnerID=40&md5=c3309a88e0a4986ccff433b13e7aed5f},
  doi = {10.1016/j.rse.2016.12.007}
}
Strozzi T, Kaab A and Schellenberger T (2017), "Frontal destabilization of Stonebreen, Edgeoya, Svalbard", Cryosphere. Vol. 11(1), pp. 553-566. Copernicus GmbH.
Abstract: In consideration of the strong atmospheric warming that has been observed since the 1990s in polar regions there is a need to quantify mass loss of Arctic ice caps and glaciers and their contribution to sea level rise. In polar regions a large part of glacier ablation is through calving of tidewater glaciers driven by ice velocities and their variations. The Svalbard region is characterized by glaciers with rapid dynamic fluctuations of different types, including irreversible adjustments of calving fronts to a changing mass balance and reversible, surge-type activities. For large areas, however, we do not have much past and current information on glacier dynamic fluctuations. Recently, through frequent monitoring based on repeat optical and synthetic aperture radar (SAR) satellite data, a number of zones of velocity increases have been observed at formerly slow-flowing calving fronts on Svalbard. Here we present the dynamic evolution of the southern lobe of Stonebreen on Edgeøya. We observe a slowly steady retreat of the glacier front from 1971 until 2011, followed by a strong increase in ice surface velocity along with a decrease of volume and frontal extension since 2012. The considerable losses in ice thickness could have made the tide-water calving glacier, which is grounded below sea level some 6 km inland from the 2014 front, more sensitive to surface meltwater reaching its bed and/or warm ocean water increasing frontal ablation with subsequent strong multi-annual ice-flow acceleration. 2017 Author(s).
BibTeX:
@article{Strozzi2017553,
  author = {Strozzi, T. and Kaab, A. and Schellenberger, T.},
  title = {Frontal destabilization of Stonebreen, Edgeoya, Svalbard},
  journal = {Cryosphere},
  publisher = {Copernicus GmbH},
  year = {2017},
  volume = {11},
  number = {1},
  pages = {553-566},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85013200625&doi=10.5194%2ftc-11-553-2017&partnerID=40&md5=3c4a835a7bf5cb56db8705076aa93b44},
  doi = {10.5194/tc-11-553-2017}
}
Strozzi T, Paul F, Wiesmann A, Schellenberger T and Kaab A (2017), "Circum-arctic changes in the flow of glaciers and ice caps from satellite SAR data between the 1990s and 2017", Remote Sensing. Vol. 9(9) MDPI AG.
Abstract: We computed circum-Arctic surface velocity maps of glaciers and ice caps over the Canadian Arctic, Svalbard and the Russian Arctic for at least two times between the 1990s and 2017 using satellite SAR data. Our analyses are mainly performed with offset-tracking of ALOS-1 PALSAR-1 (2007-2011) and Sentinel-1 (2015-2017) data. In certain cases JERS-1 SAR (1994-1998), TerraSAR-X (2008-2012), Radarsat-2 (2009-2016) and ALOS-2 PALSAR-2 (2015-2016) data were used to fill-in spatial or temporal gaps. Validation of the latest Sentinel-1 results was accomplished by means of SAR data at higher spatial resolution (Radarsat-2Wide Ultra Fine) and ground-based measurements. In general, we observe a deceleration of flow velocities for the major tidewater glaciers in the Canadian Arctic and an increase in frontal velocity along with a retreat of frontal positions over Svalbard and the Russian Arctic. However, all regions have strong accelerations for selected glaciers. The latter developments can be well traced based on the very high temporal sampling of Sentinel-1 acquisitions since 2015, revealing new insights in glacier dynamics. For example, surges on Spitsbergen (e.g., Negribreen, Nathorsbreen, Penckbreen and Strongbreen) have a different characteristic and timing than those over Eastern Austfonna and Edgeoya (e.g., Basin 3, Basin 2 and Stonebreen). Events similar to those ongoing on Eastern Austofonna were also observed over the Vavilov Ice Cap on Severnaya Zemlya and possibly Simony Glacier on Franz-Josef Land. Collectively, there seems to be a recently increasing number of glaciers with frontal destabilization over Eastern Svalbard and the Russian Arctic compared to the 1990s. 2017 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Strozzi2017,
  author = {Strozzi, T. and Paul, F. and Wiesmann, A. and Schellenberger, T. and Kaab, A.},
  title = {Circum-arctic changes in the flow of glaciers and ice caps from satellite SAR data between the 1990s and 2017},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2017},
  volume = {9},
  number = {9},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029366896&doi=10.3390%2frs9090947&partnerID=40&md5=2c9846a253dff7f157287a39eae70b21},
  doi = {10.3390/rs9090947}
}
Werner C, Baker B, Cassotto R, Magnard C, Wegmüller U and Fahnestock M (2017), "Measurement of fault creep using multi-aspect terrestrial radar interferometry at Coyote Dam", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2017-July, pp. 949-952. Institute of Electrical and Electronics Engineers Inc..
Abstract: The Calaveras fault passes directly through Coyote Dam located near Gilroy, California. The earthen structure of the dam was constructed to withstand the expected deformation due to fault creep at a rate of 10 to 15 mm/year. As part of a possible dam retrofit, the Santa Clara Valley Water District initiated a series of measurements using a Ku-Band terrestrial interferometer to accurately localize the fault trace through the dam. Measurements over the period 12-May 2016 to 18-Nov-2016 were acquired from 4 different positions situated around the down-stream face. Time series of measurements from each position were obtained after performing corrections for variable tropospheric phase delay. These measurements were combined using least-squares estimation to generate three-dimensional maps delineating both stable and rapidly deforming regions.
BibTeX:
@conference{Werner2017949,
  author = {Werner, C. and Baker, B. and Cassotto, R. and Magnard, C. and Wegmüller, U. and Fahnestock, M.},
  title = {Measurement of fault creep using multi-aspect terrestrial radar interferometry at Coyote Dam},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {2017-July},
  pages = {949-952},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041807935&doi=10.1109%2fIGARSS.2017.8127110&partnerID=40&md5=1ef364bb08405d170f725399a446bd43},
  doi = {10.1109/IGARSS.2017.8127110}
}
Wigneron J-P, Jackson T, O'Neill P, De Lannoy G, de Rosnay P, Walker J, Ferrazzoli P, Mironov V, Bircher S, Grant J, Kurum M, Schwank M, Munoz-Sabater J, Das N, Royer A, Al-Yaari A, Al Bitar A, Fernandez-Moran R, Lawrence H, Mialon A, Parrens M, Richaume P, Delwart S and Kerr Y (2017), "Modelling the passive microwave signature from land surfaces: A review of recent results and application to the L-band SMOS & SMAP soil moisture retrieval algorithms", Remote Sensing of Environment. Vol. 192, pp. 238-262. Elsevier Inc..
Abstract: Two passive microwave missions are currently operating at L-band to monitor surface soil moisture (SM) over continental surfaces. The SMOS sensor, based on an innovative interferometric technology enabling multi-angular signatures of surfaces to be measured, was launched in November 2009. The SMAP sensor, based on a large mesh reflector 6 m in diameter providing a conically scanning antenna beam with a surface incidence angle of 40°, was launched in January of 2015. Over the last decade, an intense scientific activity has focused on the development of the SM retrieval algorithms for the two missions. This activity has relied on many field (mainly tower-based) and airborne experimental campaigns, and since 2010–2011, on the SMOS and Aquarius space-borne L-band observations. It has relied too on the use of numerical, physical and semi-empirical models to simulate the microwave brightness temperature of natural scenes for a variety of scenarios in terms of system configurations (polarization, incidence angle) and soil, vegetation and climate conditions. Key components of the inversion models have been evaluated and new parameterizations of the effects of the surface temperature, soil roughness, soil permittivity, and vegetation extinction and scattering have been developed. Among others, global maps of select radiative transfer parameters have been estimated very recently. Based on this intense activity, improvements of the SMOS and SMAP SM inversion algorithms have been proposed. Some of them have already been implemented, whereas others are currently being investigated. In this paper, we present a review of the significant progress which has been made over the last decade in this field of research with a focus on L-band, and a discussion on possible applications to the SMOS and SMAP soil moisture retrieval approaches. 2017 Elsevier Inc.
BibTeX:
@article{Wigneron2017238,
  author = {Wigneron, J.-P. and Jackson, T.J. and O'Neill, P. and De Lannoy, G. and de Rosnay, P. and Walker, J.P. and Ferrazzoli, P. and Mironov, V. and Bircher, S. and Grant, J.P. and Kurum, M. and Schwank, M. and Munoz-Sabater, J. and Das, N. and Royer, A. and Al-Yaari, A. and Al Bitar, A. and Fernandez-Moran, R. and Lawrence, H. and Mialon, A. and Parrens, M. and Richaume, P. and Delwart, S. and Kerr, Y.},
  title = {Modelling the passive microwave signature from land surfaces: A review of recent results and application to the L-band SMOS & SMAP soil moisture retrieval algorithms},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2017},
  volume = {192},
  pages = {238-262},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014435143&doi=10.1016%2fj.rse.2017.01.024&partnerID=40&md5=862bf5216223b766912339d6f77db424},
  doi = {10.1016/j.rse.2017.01.024}
}
Zheng D, Wang X, Van Der Velde R, Zeng Y, Wen J, Wang Z, Schwank M, Ferrazzoli P and Su Z (2017), "L-band microwave emission of soil freeze-thaw process in the third pole environment", IEEE Transactions on Geoscience and Remote Sensing. Vol. 55(9), pp. 5324-5338. Institute of Electrical and Electronics Engineers Inc..
Abstract: Soil freeze-thaw transition monitoring is essential for quantifying climate change and hydrologic dynamics over cold regions, for instance, the Third Pole. We investigate the L-band (1.4 GHz) microwave emission characteristics of soil freeze-thaw cycle via analysis of tower-based brightness temperature (T-B) measurements in combination with simulations performed by a model of soil microwave emission considering vertical variations of permittivity and temperature. Vegetation effects are modeled using Tor Vergata discrete emission model. The ELBARA-III radiometer is installed in a seasonally frozen Tibetan grassland site to measure diurnal cycles of L-band T-B every 30 min, and supporting micrometeorological as well as volumetric soil moisture (θ) and temperature profile measurements are also conducted. Soil freezing/thawing phases are clearly distinguished by using T-B measurements at two polarizations, and further analyses show that: 1) the four-phase dielectric mixing model is appropriate for estimating permittivity of frozen soil; 2) the soil effective temperature is well comparable with the temperature at 25 cm depth when soil liquid water is freezing, while it is closer to the one measured at 5 cm when soil ice is thawing; and 3) the impact on T-B caused by diurnal changes of ground permittivity is dominating the impact of changing ground temperature. Moreover, the simulations performed with the integrated Tor Vergata emission model and Noah land surface model indicate that the T-B signatures of diurnal soil freeze-thaw cycle is more sensitive to the liquid water content of the soil surface layer than the in situ measurements taken at 5 cm depth.
BibTeX:
@article{Zheng20175324,
  author = {Zheng, D. and Wang, X. and Van Der Velde, R. and Zeng, Y. and Wen, J. and Wang, Z. and Schwank, M. and Ferrazzoli, P. and Su, Z.},
  title = {L-band microwave emission of soil freeze-thaw process in the third pole environment},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2017},
  volume = {55},
  number = {9},
  pages = {5324-5338},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020422898&doi=10.1109%2fTGRS.2017.2705248&partnerID=40&md5=e01ddc01e38a4314b7294baf56980ade},
  doi = {10.1109/TGRS.2017.2705248}
}
Baffelli S, Frey O, Werner C and Hajnsek I (2016), "System characterization and polarimetric calibration of theku-band advanced polarimetric interferometer", In Proc. European Conf. Synthetic Aperture Radar.
Abstract: This paper addresses the system characterization and the polarimetric calibration of the Ku-Band Advanced Polarimetric Interferometer (KAPRI). KAPRI is an FMCW ground-based real aperture radar system that uses slotted waveguide antennas. The rotation of the antennas introduces undesired phase ramps in azimuth. We present a geometrical model to account for this phase, and propose a method to correct it. Experimental data with a set of trihedral corner reflectors (TCR) in the scene was acquired with the system. A linear phase variation of 30 degrees was observed over the TCR which was geometrically modeled and successfully corrected. VDE VERLAG GMBH · Berlin · Offenbach.
BibTeX:
@conference{Baffelli2016,
  author = {Baffelli, S. and Frey, O. and Werner, C. and Hajnsek, I.},
  title = {System characterization and polarimetric calibration of theku-band advanced polarimetric interferometer},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2016},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85001043425&partnerID=40&md5=53410bcfa53436e51b7797e9059b133d}
}
Bartsch A, Grosse G, Kaab A, Westermann S, Strozzi T, Wiesmann A, Duguay C, Seifert F, Obu J and Goler R (2016), "GlobPermafrost - How space-based earth observation supports understanding of permafrost", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: The GlobPermafrost project develops, validates and implements Earth Observation (EO) products to support research communities and international organisations in their work on better understanding permafrost characteristics and dynamics. To facilitate usability of these products by the target audience, user requirements with respect to the planned products have been requested and collected through an online community survey as well as by interview. This paper provides an overview on the planned thematic EO products as well as results of the user requirement survey.
BibTeX:
@conference{Bartsch2016,
  author = {Bartsch, A. and Grosse, G. and Kaab, A. and Westermann, S. and Strozzi, T. and Wiesmann, A. and Duguay, C. and Seifert, F.M. and Obu, J. and Goler, R.},
  editor = {Ouwehand L.},
  title = {GlobPermafrost - How space-based earth observation supports understanding of permafrost},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988451789&partnerID=40&md5=fa6e598fa0ef5ccb81f7e6d7adfaf8e8}
}
Cartus O and Santoro M (2016), "Multi-scale mapping of forest growing stock volume using Envisat ASAR, Alos Palsar, Landsat, and icesat glas", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: Multi-scale approaches for mapping aboveground biomass globally are evaluated that exploit the multitemporal archive of low-resolution (1 km) ENVISAT ASAR C-band observations and ca. 30 m resolution ALOS PALSAR L-band and Landsat mosaics. The BIOMASAR algorithm, which was initially developed for ENVISAT ASAR C-band data and boreal forest [1], is deployed to map growing stock volume, a proxy for aboveground biomass, globally at 1 km resolution. We explore different options for improving ASAR based maps using high resolution data. Two approaches are pursued: 1) the BIOMASAR algorithm adopted for Lband, 2) a simple re-scaling of ASAR derived estimates of growing stock volume from 1 km pixel posting to 30 m using PALSAR and Landsat data [2]. The initial results for different forest ecosystems suggest that both approaches allow for improved estimates, albeit with the expected limitations in high biomass forests.
BibTeX:
@conference{Cartus2016,
  author = {Cartus, O. and Santoro, M.},
  editor = {Ouwehand L.},
  title = {Multi-scale mapping of forest growing stock volume using Envisat ASAR, Alos Palsar, Landsat, and icesat glas},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988529657&partnerID=40&md5=810c108c038fc16ee38bac3f0da67203}
}
Casu F and Manconi A (2016), "Four-dimensional surface evolution of active rifting from spaceborne SAR data", Geosphere. Vol. 12(3), pp. 697-705. Geological Society of America.
Abstract: We present a case study for detecting the four-dimensional (4-D) displacement of rift zones affected by large-magnitude deformation, by using spaceborne synthetic aperture radar (SAR) data. Our method relies on the combination of displacement time series generated from pixel offset estimates on the amplitude information of multitemporal SAR images acquired from different orbit passes and with different looking geometries. We successfully applied the technique on advanced SAR (ASAR) Envisat data acquired from ascending and descending orbits over the Afar rift zone (Ethiopia) during the 2006-2010 time span. Our results demonstrate the effectiveness of the proposed technique to retrieve the full 4-D (i.e., north, east, up, and time) displacement field associated with active rifting affected by very large-magnitude deformation. 2016 The Authors.
BibTeX:
@article{Casu2016697,
  author = {Casu, F. and Manconi, A.},
  title = {Four-dimensional surface evolution of active rifting from spaceborne SAR data},
  journal = {Geosphere},
  publisher = {Geological Society of America},
  year = {2016},
  volume = {12},
  number = {3},
  pages = {697-705},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84980377996&doi=10.1130%2fGES01225.1&partnerID=40&md5=a649acb163efff18890c702170313534},
  doi = {10.1130/GES01225.1}
}
Cignetti M, Manconi A, Manunta M, Giordan D, De Luca C, Allasia P and Ardizzone F (2016), "Taking advantage of the ESA G-POD service to study ground deformation processes in high mountain areas: A Valle d'Aosta case study, Northern Italy", Remote Sensing. Vol. 8(10) MDPI AG.
Abstract: This paper presents a methodology taking advantage of the GPOD-SBAS service to study the surface deformation information over high mountain regions. Indeed, the application of the advanced DInSAR over the arduous regions represents a demanding task. We implemented an iterative selection procedure of the most suitable SAR images, aimed to preserve the largest number of SAR scenes, and the fine-tuning of several advanced configuration parameters. This method is aimed at minimizing the temporal decorrelation effects, principally due to snow cover, and maximizing the number of coherent targets and their spatial distribution. The methodology is applied to the Valle d'Aosta (VDA) region, Northern Italy, an alpine area characterized by high altitudes, complex morphology, and susceptibility to different mass wasting phenomena. The approach using GPOD-SBAS allows for the obtainment of mean deformation velocity maps and displacement time series relative to the time period from 1992 to 2000, relative to ESR-1/2, and from 2002 to 2010 for ASAR-Envisat. Our results demonstrate how the DInSAR application can obtain reliable information of ground displacement over time in these regions, and may represent a suitable instrument for natural hazards assessment. 2016 by the authors.
BibTeX:
@article{Cignetti2016,
  author = {Cignetti, M. and Manconi, A. and Manunta, M. and Giordan, D. and De Luca, C. and Allasia, P. and Ardizzone, F.},
  title = {Taking advantage of the ESA G-POD service to study ground deformation processes in high mountain areas: A Valle d'Aosta case study, Northern Italy},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2016},
  volume = {8},
  number = {10},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84992521865&doi=10.3390%2frs8100852&partnerID=40&md5=f6400d8dd3d288d460848661930e5407},
  doi = {10.3390/rs8100852}
}
De Santis F, Coviello V, Manconi A, Picozzi M and Godio A (2016), "Characterization of mass movements in the Italian Alps using regional seismic networks", In Landslides and Engineered Slopes. Experience, Theory and Practice. Vol. 2, pp. 771-780. Taylor and Francis Inc..
Abstract: In order to evaluate the exploitation of broad-band seismic networks for landslide characterization, we selected a number of well known mass movements occurred in the Italian Alps, characterized by volumes ranging between 25.000 and 34.000.000 cubic meters and different failure dynamics. We analyzed the related seismic signals recorded by seismic stations located, on average, 50 km away from the sources, focusing the study on the 1-30 Hz frequency band. The time frequency domain analysis of data allowed identifying some common signal characteristics, including emergent onsets on all channels, slowly decaying tails and a triangular spectrogram shape. Moreover, the time series of seismic record allowed identifying the different sub-events in which it is possible to divide a landslide, giving a first qualitative characterization of these phenomena from seismic records. In this work, the selected events are described and the associated seismograms are presented and analyzed together with a first discussion of their spectral characteristics. 2016 Associazione Geotecnica Italiana, Rome, Italy.
BibTeX:
@conference{DeSantis2016771,
  author = {De Santis, F. and Coviello, V. and Manconi, A. and Picozzi, M. and Godio, A.},
  title = {Characterization of mass movements in the Italian Alps using regional seismic networks},
  booktitle = {Landslides and Engineered Slopes. Experience, Theory and Practice},
  publisher = {Taylor and Francis Inc.},
  year = {2016},
  volume = {2},
  pages = {771-780},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984813542&partnerID=40&md5=86337d495084bb0e2e109856387bc874}
}
Devanthery N, Luzi G, Stramondo S, Bignami C, Pierdicca N, Wegmüller U, Romaniello V, Anniballe R, Piscini A, Albano M, Moro M and Crosetto M (2016), "The validation activities of the aphorism EC 7FP project, aimed at post seismic damage mapping, through a combined use of EOS and ground data", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: The estimate of damage after an earthquake using spaceborne remote sensing data is one of the main application of the change detection methodologies widely discussed in literature. APhoRISM-Advanced PRocedures for volcanIc and Seismic Monitoring is a collaborative European Commission project (FP7-SPACE-2013-1) addressing the development of innovative methods, using space and ground sensors to support the management and mitigation of the seismic and the volcanic risk. In this paper a novel approach aimed at damage assessment based on the use of a priori information derived by different sources in a preparedness phase is described and a preliminary validation is shown.
BibTeX:
@conference{Devanthery2016,
  author = {Devanthery, N. and Luzi, G. and Stramondo, S. and Bignami, C. and Pierdicca, N. and Wegmüller, U. and Romaniello, V. and Anniballe, R. and Piscini, A. and Albano, M. and Moro, M. and Crosetto, M.},
  editor = {Ouwehand L.},
  title = {The validation activities of the aphorism EC 7FP project, aimed at post seismic damage mapping, through a combined use of EOS and ground data},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988520878&partnerID=40&md5=c0586156017fcc26f2d894202b719939}
}
Fransson J, Santoro M, Wallerman J, Persson H, Monteith A, Eriksson L, Nilsson M, Olsson H, Soja M and Ulander L (2016), "Estimation of forest stem volume using ALOS-2 PALSAR-2 satellite images", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 5327-5330. Institute of Electrical and Electronics Engineers Inc..
Abstract: A first evaluation of ALOS-2 PALSAR-2 data for forest stem volume estimation has been performed at a coniferous dominated test site in southern Sweden. Both the Fine Beam Dual (FBD) polarization and the Quad-polarimetric mode were investigated. Forest plots with stem volume reaching up to a maximum of about 620 m3 ha-1 (corresponding to 370 tons ha-1) were analyzed by relating backscatter intensity to field data using an exponential model derived from the Water Cloud Model. The estimation accuracy of stem volume at plot level (0.5 ha) was calculated in terms of Root Mean Square Error (RMSE). For the best case investigated an RMSE of 39.8% was obtained using one of the FBD HV-polarized images. The corresponding RMSE for the FBD HH-polarized images was 43.9%. In the Quad-polarimetric mode the lowest RMSE at HV- and HH-polarization was found to be 43.1% and 66.1%, respectively. 2016 IEEE.
BibTeX:
@conference{Fransson20165327,
  author = {Fransson, J.E.S. and Santoro, M. and Wallerman, J. and Persson, H.J. and Monteith, A.R. and Eriksson, L.E.B. and Nilsson, M. and Olsson, H. and Soja, M.J. and Ulander, L.M.H.},
  title = {Estimation of forest stem volume using ALOS-2 PALSAR-2 satellite images},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {5327-5330},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007492106&doi=10.1109%2fIGARSS.2016.7730388&partnerID=40&md5=5709da3779005e3bdf1c54c33f354c72},
  doi = {10.1109/IGARSS.2016.7730388}
}
Frey O, Werner C, Caduff R and Wiesmann A (2016), "A time series of tomographic profiles of a snow pack measured with SnowScat at X-/Ku-band", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 17-20. Institute of Electrical and Electronics Engineers Inc..
Abstract: The SnowScat device is a ground-based stepped-frequency continuous-wave (SFCW) scatterometer supporting fully-polarimetric measurements within a frequency band from 9.2 to 17.8 GHz. It was originally designed to support the investigation and validation of Snow Water Equivalent (SWE) retrieval algorithms in the context of the development of the deselected COld REgions Hydrology High-resolution Observatory (CoReH20) candidate Earth Explorer 7 mission. Recently, the SnowScat hardware has been enhanced to also provide a tomographic profiling mode which allows to obtain high-resolution 2-D vertical profiles that may provide further insight into the electromagnetic interaction within layered snow packs. In winter 2014/2015, a first test campaign was carried out yielding a successful proof of concept of the enhanced hardware, tomographic measurement, and basic processing concept. In Nov/Dec 2015, the SnowScat device was then installed as a part of the SnowLab experiment at a test site on 1700m altitude close to the Grimsel pass in Switzerland. A comprehensive time series of tomographic profiles of a snow pack was acquired until end of March, 2016. In this paper, we present and discuss first results of this new time series of tomographic profiles including 2-D vertical profiles of backscatter, phase difference between the co-polar channels, and interferometric phase difference.
BibTeX:
@conference{Frey201617,
  author = {Frey, O. and Werner, C.L. and Caduff, R. and Wiesmann, A.},
  title = {A time series of tomographic profiles of a snow pack measured with SnowScat at X-/Ku-band},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {17-20},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007480304&doi=10.1109%2fIGARSS.2016.7728995&partnerID=40&md5=169f3e23954390946faf4c117e1a3e3d},
  doi = {10.1109/IGARSS.2016.7728995}
}
Frey O, Werner CL, Caduff R and Wiesmann A (2016), "A time series of SAR tomographic profiles of a snowpack", In Proc. European Conf. Synthetic Aperture Radar.
Abstract: Recently, the SnowScat hardware 'a tower-mounted fully-polarimetric scatterometer at X-/Ku-band' has been enhanced to also provide a tomographic profiling mode which allows to obtain high-resolution 2-D vertical profiles that may provide further insights into the electromagnetic interaction within layered snowpacks. In winter 2014/2015, a first test campaign was carried out yielding a successful proof of concept of the hardware, tomographic measurement, and basic processing concept. As a follow-up, in Nov/Dec 2015, the SnowScat device was installed at a test site on 1700m altitude close to the Grimsel pass in Switzerland. Since then it has been acquiring a time series of tomographic profiles of a snow pack. In this paper, we present and discuss first results of this new time series. VDE VERLAG GMBH · Berlin · Offenbach.
BibTeX:
@conference{Frey2016,
  author = {Frey, O. and Werner, C. L. and Caduff, R. and Wiesmann, A.},
  title = {A time series of SAR tomographic profiles of a snowpack},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2016},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85000961950&partnerID=40&md5=c5e1403b4f593fd9c7f119d73eeebc80}
}
Hocke K, Guzmán F, Cossu F and Matzler C (2016), "Cloud fraction of liquid water clouds above Switzerland over the last 12 years", Climate. Vol. 4(4) MDPI AG.
Abstract: Cloud fraction (CF) plays a crucial role in the Earth's radiative energy budget and thus in the climate. Reliable long-term measurements of CF are rare. The ground-based TROpospheric WAter RAdiometer (TROWARA) at Bern, Switzerland continuously measures integrated liquid water and infrared brightness temperature with a time resolution of 6-11 s since 2004. The view direction of TROWARA is constant (zenith angle 50°), and all radiometer channels see the same volume of the atmosphere. TROWARA is sensitive to liquid water clouds while the microwave signal of ice clouds is negligible. By means of the measurement data we derived CF of thin liquid water clouds (1); thick supercooled liquid water clouds (2); thick warm liquid water clouds (3) and all liquid water clouds (4). The article presents the time series and seasonal climatologies of these four classes of CF. CF of thick supercooled liquid water clouds is larger than 15% from November to March. A significant negative trend of -0.29% ± 0.10%/yr is found for CF of thin liquid water clouds. No trends are found for the other classes (2, 3, 4) since their strong natural variability impedes a significant trend. However, CF of warm liquid water clouds increased by about +0.51% ± 0.27%/yr from 2004 to 2015. Finally, we performed a Mann-Kendall analysis of seasonal trends which gave several significant trends in the classes 1, 2 and 3. 2016 by the authors.
BibTeX:
@article{Hocke2016,
  author = {Hocke, K. and Guzmán, F.N. and Cossu, F. and Matzler, C.},
  title = {Cloud fraction of liquid water clouds above Switzerland over the last 12 years},
  journal = {Climate},
  publisher = {MDPI AG},
  year = {2016},
  volume = {4},
  number = {4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029378784&doi=10.3390%2fcli4040048&partnerID=40&md5=67025ab023bba3e02a25d33361b3e2e2},
  doi = {10.3390/cli4040048}
}
Klimes J, Novotný J, Novotná I, de Urries B, Vilímek V, Emmer A, Strozzi T, Kusák M, Rapre A, Hartvich F and Frey H (2016), "Landslides in moraines as triggers of glacial lake outburst floods: example from Palcacocha Lake (Cordillera Blanca, Peru)", Landslides. Vol. 13(6), pp. 1461-1477. Springer Verlag.
Abstract: Studies focusing on moraine deposits which slide into glacial lakes are scarce, even though they can trigger impact waves responsible for generating glacial lake outburst floods. We focused on landslides in lateral moraines as possible triggers. Detailed geomorphological, geophysical, and satellite radar interferometric investigations of the Palcacocha Lake moraine (Cordillera Blanca, Peru) together with laboratory tests on samples from the site provided data for slope stability calculations using GeoSlope software and hydrodynamic impact wave modeling using the Iber code. We identified landslides that could affect Palcacocha Lake and calculated their stability (factor of safety) under specified conditions, including variable water saturation and earthquake effects. Calculations showed that the moraine slopes are close to the threshold value (Fs = 1) for stability and are especially sensitive to water saturation. The height of impact waves triggered by a landslide in 2003 and the potential wave heights from newly identified, possibly active landslides were calculated, based on landslide volume estimates, detailed lake bathymetry, and basin topography. Results show that potential future landslide-triggered waves could have similar properties to the 2003 impact wave. Evidence gathered in this study suggests that glacial lake outburst floods triggered by landslides from moraines, however, would be probably smaller than floods resulting from other types of slope processes (e.g., ice/rock avalanches) if dam breach is not taken into account. This assumption has to be critically evaluated against site-specific conditions at a given lake and any possible environmental factors, such as climate change or earthquake that may mobilize larger volumes of moraine material. 2016, Springer-Verlag Berlin Heidelberg.
BibTeX:
@article{Klimes20161461,
  author = {Klimes, J. and Novotný, J. and Novotná, I. and de Urries, B.J. and Vilímek, V. and Emmer, A. and Strozzi, T. and Kusák, M. and Rapre, A.C. and Hartvich, F. and Frey, H.},
  title = {Landslides in moraines as triggers of glacial lake outburst floods: example from Palcacocha Lake (Cordillera Blanca, Peru)},
  journal = {Landslides},
  publisher = {Springer Verlag},
  year = {2016},
  volume = {13},
  number = {6},
  pages = {1461-1477},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978906348&doi=10.1007%2fs10346-016-0724-4&partnerID=40&md5=fc0c4fe1213a2e27cbf17eed905bda22},
  doi = {10.1007/s10346-016-0724-4}
}
Kos A, Amann F, Strozzi T, Delaloye R, von Ruette J and Springman S (2016), "Contemporary glacier retreat triggers a rapid landslide response, Great Aletsch Glacier, Switzerland", Geophysical Research Letters. Vol. 43(24), pp. 12,466-12,474. Blackwell Publishing Ltd.
Abstract: The destabilization and catastrophic failure of landslides triggered by retreating glaciers is an expected outcome of global climate change and poses a significant threat to inhabitants of glaciated mountain valleys around the globe. Of particular importance are the formation of landslide-dammed lakes, outburst floods, and related sediment entrainment. Based on field observations and remote sensing of a deep-seated landslide, located at the present-day terminus of the Great Aletsch Glacier, we show that the spatiotemporal response of the landslide to glacier retreat is rapid, occurring within a decade. Our observations uniquely capture the critical period of increase in slope deformations, onset of failure, and show that measured displacements at the crown and toe regions of the landslide demonstrate a feedback mechanism between glacier ice reduction and response of the entire landslide body. These observations shed new light on the geomorphological processes of landslide response in paraglacial environments, which were previously understood to occur over significantly longer time periods. 2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Kos201612,
  author = {Kos, A. and Amann, F. and Strozzi, T. and Delaloye, R. and von Ruette, J. and Springman, S.},
  title = {Contemporary glacier retreat triggers a rapid landslide response, Great Aletsch Glacier, Switzerland},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2016},
  volume = {43},
  number = {24},
  pages = {12,466-12,474},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85008474065&doi=10.1002%2f2016GL071708&partnerID=40&md5=34354a42c9b724adb8dc10abf0fec2e2},
  doi = {10.1002/2016GL071708}
}
Lamarche C, Santoro M, Bontemps S, D'Andrimont R, Giustarini L, Brockmann C, Militzer J, Defourny P and Arino O (2016), "A global map of open water bodies and coastlines at 150 M based on synergies between SAR and optical datasets", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: In the framework of the European Space Agency Climate Change Initiative, a global map of open water bodies and coastlines at 150 m resolution was derived using synthetic aperture radar and optical datasets including observations from the 2000-2012 period. This map and constitutive inputs were assessed qualitatively and quantitatively against a global reference validation database of 2110 samples, intentionally biased towards areas prone to errors in characterizing water bodies. It yielded more informative quality assessment figures in terms of the relative improvement between products and types of errors. The overall accuracy of the Climate Change Initiative global map of open water bodies at 150 m was found equal to 99% with a F-score of 89% for class water, significantly superior to its constitutive input water bodies datasets. The dataset is openly available at: http://maps.elie.ucl.ac.be/CCI/viewer since 2016.
BibTeX:
@conference{Lamarche2016,
  author = {Lamarche, C. and Santoro, M. and Bontemps, S. and D'Andrimont, R. and Giustarini, L. and Brockmann, C. and Militzer, J. and Defourny, P. and Arino, O.},
  editor = {Ouwehand L.},
  title = {A global map of open water bodies and coastlines at 150 M based on synergies between SAR and optical datasets},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988517298&partnerID=40&md5=aff6d0866f2944547a0c1991c81d59da}
}
Leinss S, Lowe H, Proksch M, Lemmetyinen J, Wiesmann A and Hajnsek I (2016), "Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series", Cryosphere. Vol. 10(4), pp. 1771-1797. Copernicus GmbH.
Abstract: The snow microstructure, i.e., the spatial distribution of ice and pores, generally shows an anisotropy which is driven by gravity and temperature gradients and commonly determined from stereology or computer tomography. This structural anisotropy induces anisotropic mechanical, thermal, and dielectric properties. We present a method based on radio-wave birefringence to determine the depth-averaged, dielectric anisotropy of seasonal snow with radar instruments from space, air, or ground. For known snow depth and density, the birefringence allows determination of the dielectric anisotropy by measuring the copolar phase difference (CPD) between linearly polarized microwaves propagating obliquely through the snowpack. The dielectric and structural anisotropy are linked by Maxwell- Garnett-type mixing formulas. The anisotropy evolution of a natural snowpack in Northern Finland was observed over four winters (2009-2013) with the ground-based radar instrument "SnowScat". The radar measurements indicate horizontal structures for fresh snow and vertical structures in old snow which is confirmed by computer tomographic in situ measurements. The temporal evolution of the CPD agreed in ground-based data compared to space-borne measurements from the satellite TerraSAR-X. The presented dataset provides a valuable basis for the development of new snow metamorphism models which include the anisotropy of the snow microstructure. Author(s) 2016.
BibTeX:
@article{Leinss20161771,
  author = {Leinss, S. and Lowe, H. and Proksch, M. and Lemmetyinen, J. and Wiesmann, A. and Hajnsek, I.},
  title = {Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series},
  journal = {Cryosphere},
  publisher = {Copernicus GmbH},
  year = {2016},
  volume = {10},
  number = {4},
  pages = {1771-1797},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983449810&doi=10.5194%2ftc-10-1771-2016&partnerID=40&md5=bd4e980a1f8e1feade6647ec0473a98f},
  doi = {10.5194/tc-10-1771-2016}
}
Lemmetyinen J, Kontu A, Pulliainen J, Vehvilainen J, Rautiainen K, Wiesmann A, Matzler C, Werner C, Rott H, Nagler T, Schneebeli M, Proksch M, Schuttemeyer D, Kern M and Davidson M (2016), "Nordic Snow Radar Experiment", Geoscientific Instrumentation, Methods and Data Systems. Vol. 5(2), pp. 403-415. Copernicus GmbH.
Abstract: The objective of the Nordic Snow Radar Experiment (NoSREx) campaign was to provide a continuous time series of active and passive microwave observations of snow cover at a representative location of the Arctic boreal forest area, covering a whole winter season. The activity was a part of Phase A studies for the ESA Earth Explorer 7 candidate mission CoReH2O (Cold Regions Hydrology High-resolution Observatory).

The NoSREx campaign, conducted at the Finnish Meteorological Institute Arctic Research Centre (FMI-ARC) in Sodankyla, Finland, hosted a frequency scanning scatterometer operating at frequencies from X-to Ku-band. The radar observations were complemented by a microwave dual-polarization radiometer system operating from X-to W-bands. In situ measurements consisted of manual snow pit measurements at the main test site as well as extensive automated measurements on snow, ground and meteorological parameters.

This study provides a summary of the obtained data, detailing measurement protocols for each microwave instrument and in situ reference data. A first analysis of the microwave signatures against snow parameters is given, also comparing observed radar backscattering and microwave emission to predictions of an active/passive forward model.

All data, including the raw data observations, are available for research purposes through the European Space Agency and the Finnish Meteorological Institute. A consolidated dataset of observations, comprising the key microwave and in situ observations, is provided through the ESA campaign data portal to enable easy access to the data. 2016 Author(s).
BibTeX:
@article{Lemmetyinen2016403,
  author = {Lemmetyinen, J. and Kontu, A. and Pulliainen, J. and Vehvilainen, J. and Rautiainen, K. and Wiesmann, A. and Matzler, C. and Werner, C. and Rott, H. and Nagler, T. and Schneebeli, M. and Proksch, M. and Schuttemeyer, D. and Kern, M. and Davidson, M.W.J.},
  title = {Nordic Snow Radar Experiment},
  journal = {Geoscientific Instrumentation, Methods and Data Systems},
  publisher = {Copernicus GmbH},
  year = {2016},
  volume = {5},
  number = {2},
  pages = {403-415},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84987608682&doi=10.5194%2fgi-5-403-2016&partnerID=40&md5=3b91c6f1f3bedba1173e1448339be130},
  doi = {10.5194/gi-5-403-2016}
}
Lemmetyinen J, Schwank M, Derksen C, Roy A, Colliander A, Rautiainen K and Pulliainen J (2016), "Retrieval of snow parameters from L-band observations - Application for SMOS and SMAP", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 7067-7070. Institute of Electrical and Electronics Engineers Inc..
Abstract: Recent theoretical and experimental studies have indicated the feasibility of passive microwave L-band observations for observing dry snow cover characteristics, namely snow density in the lower approx.. 10 cm of the snowpack. The sensitivity of L-band emission to snow density is based on the dual influence of refraction and impedance matching on observed brightness temperature with changing effective snow permittivity. The permittivity of pure, dry snow, on the other hand, depends largely on snow density. In this study, we expand the theoretical and experimental results of retrieving dry snow density to passive L-band satellite observations. Such retrievals could be appealing in the context of improving satellite based retrievals of e.g. Snow Water Equivalent (SWE) using other sensors. Retrievals are applied to both multi-angular observations from the ESA SMOS mission, and observations of the NASA SMAP radiometer on a single angle of observation. While in theory the multi-angular approach is preferable, improved RFI mitigation in SMAP provides more spatially and temporally more stable retrievals. The applied dual-parameter retrieval scheme produces also an estimate of ground permittivity; experimental data showed dry snow cover to have a clear influence on ground permittivity retrievals, implicating that even dry snow cover is non-negligible also in retrievals of soil moisture from L-band observations. 2016 IEEE.
BibTeX:
@conference{Lemmetyinen20167067,
  author = {Lemmetyinen, J. and Schwank, M. and Derksen, C. and Roy, A. and Colliander, A. and Rautiainen, K. and Pulliainen, J.},
  title = {Retrieval of snow parameters from L-band observations - Application for SMOS and SMAP},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {7067-7070},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007463527&doi=10.1109%2fIGARSS.2016.7730843&partnerID=40&md5=b8232472bdd88fa6a46ab862d654fa65},
  doi = {10.1109/IGARSS.2016.7730843}
}
Lemmetyinen J, Schwank M, Rautiainen K, Kontu A, Parkkinen T, Matzler C, Wiesmann A, Wegmüller U, Derksen C, Toose P, Roy A and Pulliainen J (2016), "Snow density and ground permittivity retrieved from L-band radiometry: Application to experimental data", Remote Sensing of Environment. Vol. 180, pp. 377-391. Elsevier Inc..
Abstract: The potential of retrieving the bottom layer snow density and soil permittivity under dry snow cover conditions from L-band passive microwave observations was analyzed using multi-angular brightness temperatures measured at horizontal and vertical polarization over two test sites in northern Finland. The near-continuous time series of L-band brightness temperatures covers a total of six winter seasons, over both dry mineral soil in a forest clearing, and organic soil over a wetland site. Detailed measurements of snow and soil conditions are available from both sites. Complementing a previous theoretical study, we show that dry snow cover influences the observed L-band brightness temperatures as a result of both impedance matching and changes in the refraction angle at the snow-soil interface. Exploiting these effects, we demonstrate the retrieval of the bottom layer snow density and the influence of dry snow cover on simultaneously retrieved soil permittivity - a consideration which is currently not accounted for in Soil Moisture and Ocean Salinity (SMOS) retrievals of soil permittivity in the presence of dry snow. Depending on season, the mean bias error between retrieved and in situ snow density measured in the lower snow layers was between -6 kg m-3 and 15 kg m-3 for the forest clearing site, and between 37 kg m-3 and 90 kg m-3 for the wetland site, demonstrating the feasibility of the retrieval approach at the plot scale. In winter conditions, the ground permittivity retrieved without considering the impact of dry snow on L-band emission was, on average, 35% lower for both test sites, which indicates possible errors in current SMOS ground permittivity retrievals under dry snow conditions. The application of SMOS data to simultaneously retrieve dry snow density and ground permittivity is a complex task due to heterogeneous land cover and snow/soil conditions within SMOS pixels (≈45 km resolution). An approach that considers land cover variations and the spatial variability of snow cover is required to fully determine the feasibility of the methodology to aid e.g. improving estimates snow water equivalent from other sensors, and to take into account effects of dry snow in SMOS-based retrievals of ground permittivities. The results should also be applicable to other L-band sensors in space, such as the recently launched NASA Soil Moisture Active Passive (SMAP) mission. 2016 Elsevier Inc.
BibTeX:
@article{Lemmetyinen2016377,
  author = {Lemmetyinen, J. and Schwank, M. and Rautiainen, K. and Kontu, A. and Parkkinen, T. and Matzler, C. and Wiesmann, A. and Wegmüller, U. and Derksen, C. and Toose, P. and Roy, A. and Pulliainen, J.},
  title = {Snow density and ground permittivity retrieved from L-band radiometry: Application to experimental data},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2016},
  volume = {180},
  pages = {377-391},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957640848&doi=10.1016%2fj.rse.2016.02.002&partnerID=40&md5=8734b18ef54aaabcf49e946b38a664f9},
  doi = {10.1016/j.rse.2016.02.002}
}
Lin C-C, Rommen B, Floury N, Schuttemeyer D, Davidson M, Kern M, Kontu A, Lemmetyinen J, Pulliainen J, Wiesmann A, Werner C, Matzler C, Schneebeli M, Proksch M and Nagler T (2016), "Active Microwave Scattering Signature of Snowpack - Continuous Multiyear SnowScat Observation Experiments", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 9(8), pp. 3849-3869. Institute of Electrical and Electronics Engineers.
Abstract: European Space Agency's SnowScat instrument is a real aperture scatterometer which was developed by Gamma Remote Sensing AG. It operates in a continuous-wave mode, covers a frequency range of 9.15-17.9 GHz in a user-defined frequency-step and has a full polarimetric capability. The measurement campaigns were started first in February 2009 at Weissfluhjoch, in Davos, Switzerland, as an initial test of the instrument over a deep alpine snowpack. Physical characterizations of the snowpack and meteorological measurements were carried out, which formed a detailed in situ dataset. SnowScat was then moved to Sodankyla in Finland in early November 2009, a site of the Finnish Meteorological Institute in Lapland. In addition to the in situ snowpack characterizations and meteorological observations, continuous passive microwave observations were also performed. During the 2012-2013 winter period, a vertical time-domain snow profiling experiment was carried out in addition for resolving the scattering contributions from the snow layers of different physical properties. This paper summarizes the results of the SnowScat observations and initial comparisons against the in situ meteorological and snowpack data. The Sodankyla campaign data evidenced the high variability of the radar backscatter behavior of snowpack from year to year, which indicates its strong dependency on changing snow microstructure. Indeed, the snow microstructure is continuously driven by snow metamorphism, which are further affected by meteorological conditions and their interannual variability. The backscattering property of snowpack in the range X- to Ku-band for all polarizations appeared to be dominated by its microstructural morphology and underlying ground conditions, and to a lesser extent by the snow depth, or its snow-water-equivalent. 2016 IEEE.
BibTeX:
@article{Lin20163849,
  author = {Lin, C.-C. and Rommen, B. and Floury, N. and Schuttemeyer, D. and Davidson, M.W.J. and Kern, M. and Kontu, A. and Lemmetyinen, J. and Pulliainen, J. and Wiesmann, A. and Werner, C.L. and Matzler, C. and Schneebeli, M. and Proksch, M. and Nagler, T.},
  title = {Active Microwave Scattering Signature of Snowpack - Continuous Multiyear SnowScat Observation Experiments},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2016},
  volume = {9},
  number = {8},
  pages = {3849-3869},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84971516920&doi=10.1109%2fJSTARS.2016.2560168&partnerID=40&md5=136501a759db78ffef951c17a3f32059},
  doi = {10.1109/JSTARS.2016.2560168}
}
Magnard C, Frioud M, Small D, Brehm T and Meier E (2016), "Analysis of a Maximum Likelihood Phase Estimation Method for Airborne Multibaseline SAR Interferometry", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 9(3), pp. 1072-1085. Institute of Electrical and Electronics Engineers.
Abstract: It has been shown using simulated data that phase estimation of cross-track multibaseline synthetic aperture radar (SAR) interferometric data was most efficiently achieved through a maximum likelihood (ML) method. In this paper, we apply and assess the ML approach on real data, acquired with an experimental Ka-band multibaseline system. Compared to simulated data, dealing with real data implies that several calibration steps be carried out to ensure that the data fit the model. A processing chain was, therefore, designed, including steps responsible for compensating for imperfections observed in the data, such as beam elevation angle dependent phase errors or phase errors caused by imperfect motion compensation. The performance of the ML phase estimation was evaluated by comparing it to results based on a coarse-to-fine (C2F) algorithm, where information from the shorter baselines was used only to unwrap the phase from the longest available baseline. For this purpose, flat areas with high coherence and homogeneous texture were selected in the acquired data. The results show that with only four looks, the noise level was marginally better with the C2F approach and contained fewer outliers. However, with more looks, the ML method consistently delivered better results: noise variance with the C2F approach was slightly but steadily larger than the variance obtained with ML method. 2015 IEEE.
BibTeX:
@article{Magnard20161072,
  author = {Magnard, C. and Frioud, M. and Small, D. and Brehm, T. and Meier, E.},
  title = {Analysis of a Maximum Likelihood Phase Estimation Method for Airborne Multibaseline SAR Interferometry},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2016},
  volume = {9},
  number = {3},
  pages = {1072-1085},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945398017&doi=10.1109%2fJSTARS.2015.2487685&partnerID=40&md5=b23300a980e6af7335ed16ab81681702},
  doi = {10.1109/JSTARS.2015.2487685}
}
Magnard C, Morsdorf F, Small D, Stilla U, Schaepman M and Meier E (2016), "Single tree identification using airborne multibaseline SAR interferometry data", Remote Sensing of Environment. Vol. 186, pp. 567-580. Elsevier Inc..
Abstract: Remote sensing data allow large scale observation of forested ecosystems. Forest assessment benefits from information about individual trees. Multibaseline SAR interferometry (InSAR) is able to generate dense point clouds of forest canopies, similar to airborne laser scanning (ALS). This type of point cloud was generated using data from the Ka-band MEMPHIS system, acquired over a mainly coniferous forest near Vordemwald in the Swiss Midlands. This point cloud was segmented using an advanced clustering technique to detect individual trees and derive their positions, heights, and crown diameters. To evaluate the InSAR point cloud properties and limitations, it was compared to products derived from ALS and stereo-photogrammetry. All point clouds showed similar geolocation accuracies with 0.2–0.3 m relative shifts. Both InSAR and photogrammetry techniques yielded points predominantly located in the upper levels of the forest vegetation, while ALS provided points from the top of the canopy down to the understory and forest floor. The canopy height models agreed very well with each other, with R2 values between 0.84 and 0.89. The detected trees and their estimated physical and structural parameters were validated by comparing them to reference forestry data. A detection rate of   90% was achieved for larger trees, corresponding to half of the reference trees. The smaller trees were detected with a success rate of   50%. The tree height was slightly underestimated, with a R2 value of 0.63. The estimated crown diameter agreed on an average sense, however with a relatively low R2 value of 0.19. Very high success rates (&gt; 90%) were obtained when matching the trees detected from the InSAR-data with those detected from the ALS- and photogrammetry-data. There, InSAR tree heights were in the mean 1–1.5 m lower, with high R2 values ranging between 0.8 and 0.9. Our results demonstrate the use of millimeter wave SAR interferometry data as an alternative to ALS- and photogrammetry-based data for forest monitoring. 2016 Elsevier Inc.
BibTeX:
@article{Magnard2016567,
  author = {Magnard, C. and Morsdorf, F. and Small, D. and Stilla, U. and Schaepman, M.E. and Meier, E.},
  title = {Single tree identification using airborne multibaseline SAR interferometry data},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2016},
  volume = {186},
  pages = {567-580},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988944502&doi=10.1016%2fj.rse.2016.09.018&partnerID=40&md5=368f18f810ec94277a4f3f06cf5fc958},
  doi = {10.1016/j.rse.2016.09.018}
}
Manconi A and Giordan D (2016), "Landslide failure forecast in near-real-time", Geomatics, Natural Hazards and Risk. Vol. 7(2), pp. 639-648. Taylor and Francis Ltd..
Abstract: We present a new method to achieve failure forecast of landslide phenomena by considering near-real-time monitoring data. Starting from the inverse velocity theory, we jointly analyse landslide surface displacements on different time windows, and apply straightforward statistical methods to obtain confidence intervals on the forecasted time of failure. Our results can be relevant to support the management of early warning systems during landslide emergency conditions, also when the predefined displacement and/or velocity thresholds are exceeded. In addition, our statistical approach for the definition of confidence interval and forecast reliability can be applied also to different failure forecast methods. We applied for the first time the herein presented approach in near-real-time during the emergency scenario relevant to the reactivation of the La Saxe rockslide, a large mass wasting menacing the population of Courmayeur, northern Italy, and the important European route E25. Our results show how the application of simplified but robust forecast models can be a convenient method to manage and support early warning systems during critical situations. 2014 Taylor & Francis.
BibTeX:
@article{Manconi2016639,
  author = {Manconi, A. and Giordan, D.},
  title = {Landslide failure forecast in near-real-time},
  journal = {Geomatics, Natural Hazards and Risk},
  publisher = {Taylor and Francis Ltd.},
  year = {2016},
  volume = {7},
  number = {2},
  pages = {639-648},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955655481&doi=10.1080%2f19475705.2014.942388&partnerID=40&md5=b22721088e1c33711042e5d2481cf137},
  doi = {10.1080/19475705.2014.942388}
}
Manconi A, Picozzi M, Coviello V, De Santis F and Elia L (2016), "Real-time detection, location, and characterization of rockslides using broadband regional seismic networks", Geophysical Research Letters. Vol. 43(13), pp. 6960-6967. Blackwell Publishing Ltd.
Abstract: We propose a new real-time approach to detect, locate, and estimate the volume of rockslides by analyzing waveforms acquired from broadband regional seismic networks. The identification of signals generated by rockslides from other sources, such as natural and/or induced earthquakes, is accomplished by exploiting the ratio between local magnitudes (ML) and duration magnitudes (MD). We found that signals associated with rockslides have ML/MD &lt; 0.8, while for earthquakes ML/MD ≅ 1. In addition, we derived an empirical relationship between MD and rockslide volumes, obtaining a preliminary characterization of rockslide volume within seconds after their occurrence. The key points of this study are presented by testing the hypothesis on a recent rockslide event that occurred in northern Italy. We discuss also the potential evolution of the methodology for early warning and/or rapid response purposes. 2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Manconi20166960,
  author = {Manconi, A. and Picozzi, M. and Coviello, V. and De Santis, F. and Elia, L.},
  title = {Real-time detection, location, and characterization of rockslides using broadband regional seismic networks},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2016},
  volume = {43},
  number = {13},
  pages = {6960-6967},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978138197&doi=10.1002%2f2016GL069572&partnerID=40&md5=01b54144828c709a001ccd05f35d9a50},
  doi = {10.1002/2016GL069572}
}
Pellarin T, Mialon A, Biron R, Coulaud C, Gibon F, Kerr Y, Lafaysse M, Mercier B, Morin S, Redor I, Schwank M and Volksch I (2016), "Three years of L-band brightness temperature measurements in a mountainous area: Topography, vegetation and snowmelt issues", Remote Sensing of Environment. Vol. 180, pp. 85-98. Elsevier Inc..
Abstract: L-band passive measurements (1.4 GHz) over continental areas are known to be related to surface soil moisture. Two satellite missions were recently launched to measure land surface emissions at this frequency band (SMOS-Soil Moisture and Ocean Salinity in 2009 and SMAP-Soil Moisture Active/Passive in 2015). In order to improve soil moisture retrievals from satellite data, ground-based radiometer systems operating at the same frequency were deployed over specified areas to investigate the L-band emission of various land covers under various climatological conditions. In this study, three years of L-band passive measurements from a radiometer installed on top of a steep mountain in the French Alps were analyzed and compared to L-band passive simulations. The innovative radiometer location led to large footprints due to the distance between the radiometer and the area under study. This experiment also produced microwave measurements affected by various potential difficulties typically encountered in SMOS/SMAP satellite missions: topography, heterogeneous footprints, dry/wet snow events, dew and vegetation litter. Based on in situ and modeling data, this paper investigates the potential of a radiative transfer model (L-band Microwave Emission of the Biosphere, L-MEB) to simulate L-band measurements and analyzes the differences with ELBARA observations. First, it was found that the topography generated a mixing of the horizontal and vertical polarizations. In addition, a large positive bias was found on ELBARA measurements (31 K and 12 K in horizontal and vertical polarizations respectively). Investigations showed that the sky reflection measured by the radiometer was partially substituted by land reflection coming from the surrounding topography. Second, the low-vegetation emission was investigated and highlighted the inability of the MODIS NDVI product to correctly represent the vegetation dynamics. Finally, dry snow conditions were found to have non-negligible impact at L-band and a particular signature was found during snow melting periods, with potential applications at the SMOS/SMAP spatial scales (  40 km). 2016 Elsevier Inc.
BibTeX:
@article{Pellarin201685,
  author = {Pellarin, T. and Mialon, A. and Biron, R. and Coulaud, C. and Gibon, F. and Kerr, Y. and Lafaysse, M. and Mercier, B. and Morin, S. and Redor, I. and Schwank, M. and Volksch, I.},
  title = {Three years of L-band brightness temperature measurements in a mountainous area: Topography, vegetation and snowmelt issues},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2016},
  volume = {180},
  pages = {85-98},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977746299&doi=10.1016%2fj.rse.2016.02.047&partnerID=40&md5=3aad93ffaccfe6e38b3ba9c6ffefacb1},
  doi = {10.1016/j.rse.2016.02.047}
}
Peres T, Silva J, Ruivo C, Silva P, Palomo J, Colomina I, Peña O, Hill C, Guerriero L, Carvalhais N, Erickson A and Cartus O (2016), "COREGAL: Exploring galileo E5 reflected signals for biomass applications", In 29th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2016. Vol. 2, pp. 881-891. Institute of Navigation.
Abstract: This paper presents a high-level view of the Combined Positioning-Reflectometry Galileo Code Receiver for Forest Management (COREGAL) System architecture, focusing on the development of a GNSS-P+R (Positioning and Reflectometry) receiver. The COREGAL GNSS-P+R receiver will be the main sensor platform for positioning and biomass estimation. Biomass estimation uses GNSS reflectometry (GNSS-R) signals propagated through tree canopies. The goal of this work was to develop a GNSS receiver capable of simultaneous high-accuracy positioning and raw reflected signal acquisition. The first prototype of the receiver is currently under testing. This paper also presents the results for the first COREGAL field campaign. The purpose of this test campaign was to receive GNSS signals reflected over vegetation, generating GNSS-R raw data using Galileo E5 signals.
BibTeX:
@conference{Peres2016881,
  author = {Peres, T. and Silva, J. and Ruivo, C. and Silva, P.F. and Palomo, J.M. and Colomina, I. and Peña, O. and Hill, C. and Guerriero, L. and Carvalhais, N. and Erickson, A. and Cartus, O.},
  title = {COREGAL: Exploring galileo E5 reflected signals for biomass applications},
  booktitle = {29th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2016},
  publisher = {Institute of Navigation},
  year = {2016},
  volume = {2},
  pages = {881-891},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017298599&partnerID=40&md5=a3d17aace7027011f0e446c37ab2a2ba}
}
Rautiainen K, Parkkinen T, Lemmetyinen J, Schwank M, Wiesmann A, Ikonen J, Derksen C, Davydov S, Davydova A, Boike J, Langer M, Drusch M and Pulliainen J (2016), "SMOS prototype algorithm for detecting autumn soil freezing", Remote Sensing of Environment. Vol. 180, pp. 346-360. Elsevier Inc..
Abstract: A prototype algorithm for hemispheric scale detection of autumn soil freezing using space-borne L-band passive microwave observations is presented. The methodology is based on earlier empirical and theoretical studies of L-band emission properties of freezing and thawing soils. We expand a method originally developed for soil freeze-thaw (F/T) state detection from L-band tower based observations to satellite scale, applying observations from the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission. The developed algorithm is based on first establishing spatially variable thresholds for L-band brightness temperatures representing frozen and thawed states of soil, and comparing these to current values of different indicators of soil freezing, calculated based on observed brightness temperature at different polarizations and incidence angles. An exponential relation between the freezing indicators and the depth of soil frost is developed based on a large amount of manual soil frost tube observations across Finland. An additional processing filter based on observed physical temperature and snow cover information is used to flag obvious F/T detection errors. The estimated soil F/T-states provided in this study are limited to the autumn freezing period, as melting snow in spring effectively prevents acquisition of information from the soil surface using microwaves for large areas in Northern latitudes. The F/T estimate is produced as daily information and provided in the equal-area scalable Earth (EASE) grid. Soil F/T-state is categorized into three discrete levels: 'frozen', 'partially frozen', and 'thawed', and accompanied with a quality data matrix estimating the data reliability for each freezing season separately. Comparisons to in situ data were conducted at 10 different locations in Finland, Northern America and Siberia. These comparison results indicate that the onset of autumn soil freezing can be estimated from SMOS observations to within 1 to 14 days, depending on the freezing indicator applied and the in situ data used in comparison. Although the initial results are encouraging, more comprehensive assessment of SMOS based soil F/T estimates still requires further comparison to other reference sites, particularly to sites with measurements available for all locally representative land cover types, as well as other satellite-based soil freezing products. 2016 The Authors.
BibTeX:
@article{Rautiainen2016346,
  author = {Rautiainen, K. and Parkkinen, T. and Lemmetyinen, J. and Schwank, M. and Wiesmann, A. and Ikonen, J. and Derksen, C. and Davydov, S. and Davydova, A. and Boike, J. and Langer, M. and Drusch, M. and Pulliainen, J.},
  title = {SMOS prototype algorithm for detecting autumn soil freezing},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2016},
  volume = {180},
  pages = {346-360},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957894849&doi=10.1016%2fj.rse.2016.01.012&partnerID=40&md5=cc22b602a6e0c98268768cb499152e2d},
  doi = {10.1016/j.rse.2016.01.012}
}
Robson B, Holbling D, Nuth C, Strozzi T and Dahl S (2016), "Decadal scale changes in Glacier area in the Hohe Tauern national park (Austria) determined by object-based image analysis", Remote Sensing. Vol. 8(1) MDPI AG.
Abstract: In this paper, we semi-automatically classify clean and debris-covered ice for 145 glaciers within Hohe Tauern National Park in the Austrian Alps for the years 1985, 2003, and 2013. We also map the end-summer transient snowline (TSL), which approximates the annual Equilibrium Line Altitude (ELA). By comparing our results with the Austrian Glacier Inventories from 1969 and 1998, we calculate a mean reduction in glacier area of 33% between 1969 and 2013. The total ice area reduced at a mean rate of 1.4 km2 per year. This TSL rose by 92 m between 1985 and 2013 to an altitude of 3005 m. Despite some limitations, such as some seasonal snow being present at higher elevations, as well as uncertainties related to the range of years that the LiDAR DEM was collected, our results show that the glaciers within Hohe Tauern National Park conform to the heavy shrinkage experienced in other areas of the European Alps. Moreover, we believe that Object-Based Image Analysis (OBIA) is a promising methodology for future glacier mapping. 2016 by the authors; licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Robson2016,
  author = {Robson, B.A. and Holbling, D. and Nuth, C. and Strozzi, T. and Dahl, S.O.},
  title = {Decadal scale changes in Glacier area in the Hohe Tauern national park (Austria) determined by object-based image analysis},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2016},
  volume = {8},
  number = {1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957888494&doi=10.3390%2frs8010067&partnerID=40&md5=c391c3f023955b84a9d5c6e4cc245040},
  doi = {10.3390/rs8010067}
}
Siddique M, Wegmüller U, Hajnsek I and Frey O (2016), "SAR tomography as an add-on to PSI for improved deformation sampling in urban areas: A quality assessment", In Proc. European Conf. Synthetic Aperture Radar.
Abstract: Persistent scatterer interferometry (PSI) typically rejects layovers. Therefore, layover-Affected urban areas may suffer from inadequate deformation sampling. SAR tomography, when used as an add-on to PSI, reveals additional deformation samples by resolving layovers. In this paper we quantify the relative gain in deformation sampling, while taking into account the quality of the additional (double) scatterers in terms of root-mean-square (RMS) phase deviation. We experiment on an interferometric stack of 50 TerraSAR-X stripmap images acquired over the city of Barcelona. The results show a tradeoff between the gain and the quality of the detected scatterers. For the observed urban area, we obtain a gain of 9.8% while the RMS phase deviation for 99% of the detected double scatterers is less than 1.1 radians. VDE VERLAG GMBH · Berlin · Offenbach.
BibTeX:
@conference{Siddique2016,
  author = {Siddique, M.A. and Wegmüller, U. and Hajnsek, I. and Frey, O.},
  title = {SAR tomography as an add-on to PSI for improved deformation sampling in urban areas: A quality assessment},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2016},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85000962118&partnerID=40&md5=f3f9b1c7477c96a68cf7ecd78abf9697}
}
Siddique M, Wegmüller U, Hajnsek I and Frey O (2016), "SAR tomography as an add-on to PSI: Gain in deformation sampling vis-a-vis quality of the detected scatterers", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 1452-1455. Institute of Electrical and Electronics Engineers Inc..
Abstract: SAR tomography can be used as an add-on to persistent scatterer interferometry (PSI) to increase deformation sampling in urban areas by resolving the frequently occurring layovers that are by definition rejected in the PSI processing. This paper, while focusing on the case of a typical high-rise building in layover, quantitatively assesses the potential gain in deformation sampling achieved by the added use of an advanced SAR tomographic technique relative to a PSI approach. At the same time, the quantity of the detected scatterers is weighed against their quality, as assessed on the basis of root-mean-square (RMS) phase deviation between the measurements and the model fit. The quality of the scatterers is also compared with the quality of the persistent scatterers as identified with a PSI approach. The experiments are performed on an interferometric stack of 50 TerraSAR-X stripmap mode images.
BibTeX:
@conference{Siddique20161452,
  author = {Siddique, M.A. and Wegmüller, U. and Hajnsek, I. and Frey, O.},
  title = {SAR tomography as an add-on to PSI: Gain in deformation sampling vis-a-vis quality of the detected scatterers},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {1452-1455},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007415465&doi=10.1109%2fIGARSS.2016.7729371&partnerID=40&md5=b3880819e0aff4979bb6837a4ea98747},
  doi = {10.1109/IGARSS.2016.7729371}
}
Siddique M, Wegmüller U, Hajnsek I and Frey O (2016), "Single-Look SAR Tomography as an Add-On to PSI for Improved Deformation Analysis in Urban Areas", IEEE Transactions on Geoscience and Remote Sensing. Vol. 54(10), pp. 6119-6137. Institute of Electrical and Electronics Engineers Inc..
Abstract: Persistent scatterer interferometry (PSI) is in operational use for spaceborne synthetic aperture radar (SAR)-based deformation analysis. A limitation inherently associated with PSI is that, by definition, a persistent scatterer (PS) is a single dominant scatterer. Therefore, pixels containing signal contributions from multiple scatterers, as in the case of a layover, are typically rejected in the PSI processing, which in turn limits deformation retrieval. SAR tomography has the ability to resolve layovers. This paper investigates the added value that can be achieved by operationally combining SAR tomography with a PSI approach toward the objective of improving deformation sampling in layover-affected urban areas. Different tomographic phase models are implemented and compared as regards their suitability in resolving layovers. Single-look beamforming-based tomographic inversion and a generalized likelihood ratio test (GLRT)-based detection strategy are used to detect single and double scatterers. The quantity of the detected scatterers is weighed against their quality as defined in terms of the phase deviation between the single-look complex (SLC) measurements and the tomographic model fit. The gain in deformation sampling that can be derived with tomography relative to a PSI-based analysis is quantitatively assessed, and alongside the quality of the scatterers obtained with tomography is compared with the quality of the PSs identified with a PSI approach. The experiments are performed on an interferometric stack of 50 TerraSAR-X stripmap images. The results obtained show that, although there is a tradeoff between the quantity and the quality of the detected scatterers, the tested SAR tomography approach leads to an improvement in deformation sampling in layover-affected areas. 2016 IEEE.
BibTeX:
@article{Siddique20166119,
  author = {Siddique, M.A. and Wegmüller, U. and Hajnsek, I. and Frey, O.},
  title = {Single-Look SAR Tomography as an Add-On to PSI for Improved Deformation Analysis in Urban Areas},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {54},
  number = {10},
  pages = {6119-6137},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978971071&doi=10.1109%2fTGRS.2016.2581261&partnerID=40&md5=ace29b8c6dbea23df0ecec89c7786d07},
  doi = {10.1109/TGRS.2016.2581261}
}
Thurner M, Beer C, Carvalhais N, Forkel M, Santoro M, Tum M and Schmullius C (2016), "Large-scale variation in boreal and temperate forest carbon turnover rate related to climate", Geophysical Research Letters. Vol. 43(9), pp. 4576-4585. Blackwell Publishing Ltd.
Abstract: Vegetation carbon turnover processes in forest ecosystems and their dominant drivers are far from being understood at a broader scale. Many of these turnover processes act on long timescales and include a lateral dimension and thus can hardly be investigated by plot-level studies alone. Making use of remote sensing-based products of net primary production (NPP) and biomass, here we show that spatial gradients of carbon turnover rate (k) in Northern Hemisphere boreal and temperate forests are explained by different climate-related processes depending on the ecosystem. k is related to frost damage effects and the trade-off between growth and frost adaptation in boreal forests, while drought stress and climate effects on insects and pathogens can explain an elevated k in temperate forests. By identifying relevant processes underlying broadscale patterns in k, we provide the basis for a detailed exploration of these mechanisms in field studies, and ultimately the improvement of their representations in global vegetation models (GVMs). 2016. The Authors.
BibTeX:
@article{Thurner20164576,
  author = {Thurner, M. and Beer, C. and Carvalhais, N. and Forkel, M. and Santoro, M. and Tum, M. and Schmullius, C.},
  title = {Large-scale variation in boreal and temperate forest carbon turnover rate related to climate},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2016},
  volume = {43},
  number = {9},
  pages = {4576-4585},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84969916819&doi=10.1002%2f2016GL068794&partnerID=40&md5=c6a82e3dd2c9e5b7fb2e56fdf2237827},
  doi = {10.1002/2016GL068794}
}
Tosi L, Da Lio C, Strozzi T and Teatini P (2016), "Combining L- and X-Band SAR interferometry to assess ground displacements in heterogeneous coastal environments: The Po River Delta and Venice Lagoon, Italy", Remote Sensing. Vol. 8(4) MDPI AG.
Abstract: From leveling to SAR-based interferometry, the monitoring of land subsidence in coastal transitional environments significantly improved. However, the simultaneous assessment of the ground movements in these peculiar environments is still challenging. This is due to the presence of relatively small built-up zones and infrastructures, e.g., coastal infrastructures, bridges, and river embankments, within large natural or rural lands, e.g., river deltas, lagoons, and farmland. In this paper we present a multi-band SAR methodology to integrate COSMO-SkyMed and ALOS-PALSAR images. The method consists of a proper combination of the very high-resolution X-band Persistent Scatterer Interferometry (PSI), which achieves high-density and precise measurements on single structures and constructed areas, with L-band Short-Baseline SAR Interferometry (SBAS), properly implemented to raise its effectiveness in retrieving information in vegetated and wet zones. The combined methodology is applied on the Po River Delta and Venice coastland, Northern Italy, using 16 ALOS-PALSAR and 31 COSMO-SkyMed images covering the period between 2007 and 2011. After a proper calibration of the single PSI and SBAS solution using available GPS records, the datasets have been combined at both the regional and local scales. The measured displacements range from  0 mm/yr down to -35 mm/yr. The results reveal the variable pattern of the subsidence characterizing the more natural and rural environments without losing the accuracy in quantifying the sinking of urban areas and infrastructures. Moreover, they allow improving the interpretation of the natural and anthropogenic processes responsible for the ongoing subsidence. 2016 by the authors.
BibTeX:
@article{Tosi2016b,
  author = {Tosi, L. and Da Lio, C. and Strozzi, T. and Teatini, P.},
  title = {Combining L- and X-Band SAR interferometry to assess ground displacements in heterogeneous coastal environments: The Po River Delta and Venice Lagoon, Italy},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2016},
  volume = {8},
  number = {4},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84971656721&doi=10.3390%2frs8040308&partnerID=40&md5=c88f7a7c11d231dd82b2f6ee250b62c2},
  doi = {10.3390/rs8040308}
}
Tosi L, Da Lio C, Strozzi T and Teatini P (2016), "Cosmo-SkyMed vs RADARSAT-2 for monitoring natural and anthropogenic components of the land movements in Venice", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: We present the result of a test aimed at evaluating the capability of RADARSAT-2 and COSMO-SkyMed to map the natural subsidence and ground movements induced by anthropogenic activities in the historical center of Venice. Firstly, ground movements have been retrieved at quite long- and short-term by the Persistent Scattered Interferometry (PSI) on 2008-2015 RADARSAT-2 and 2013-2015 COSMO-SkyMed image stacks, respectively. Secondly, PSI has been calibrated at regional scale using the records of permanent GPS stations. Thirdly, considering that over the last two decades "in the historical center of Venice" natural land movements are primarily ascribed to longterm processes, and those induced by human activities act at short-term, we have properly resampled 83-month RADARSAT-2 C-band and 27-month COSMOSkyMed X-band interferometric products by a common grid and processed the outcome to estimate the two components of the displacements. Results show that the average natural subsidence is generally in the range of 0.9 - 1.1 mm/yr and the anthropogenic ground movements are up to 2 mm/yr.
BibTeX:
@conference{Tosi2016a,
  author = {Tosi, L. and Da Lio, C. and Strozzi, T. and Teatini, P.},
  editor = {Ouwehand L.},
  title = {Cosmo-SkyMed vs RADARSAT-2 for monitoring natural and anthropogenic components of the land movements in Venice},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988529674&partnerID=40&md5=ca12f6624590c251311ad39284b4fd4f}
}
Wadge G, Costa A, Pascal K, Werner C and Webb T (2016), "The Variability of Refractivity in the Atmospheric Boundary Layer of a Tropical Island Volcano Measured by Ground-Based Interferometric Radar", Boundary-Layer Meteorology. Vol. 161(2), pp. 309-333. Springer Netherlands.
Abstract: For 24 h we measured continuously the variability of atmospheric refractivity over a volcano on the tropical island of Montserrat using a ground-based radar interferometer. We observed variations in phase that we interpret as due to changing water vapour on the propagation path between the radar and the volcano and we present them here in the context of the behaviour of the atmospheric boundary layer over the island. The water vapour behaviour was forced by diurnal processes, the passage of a synoptic-scale system and the presence of a plume of volcanic gas. The interferometer collected images of amplitude and phase every minute. From pairs of phase images, interferograms were calculated and analyzed every minute and averaged hourly, together with contemporaneous measurements of zenith delays estimated from a network of 14 GPS receivers. The standard deviation of phase at two sites on the volcano surface spanned a range of about 1–5 radians, the lowest values occurring at night on the lower slopes and the highest values during the day on the upper slopes. This was also reflected in spatial patterns of variability. Two-dimensional profiles of radar-measured delays were modelled using an atmosphere with water vapour content decreasing upwards and water vapour variability increasing upwards. Estimates of the effect of changing water vapour flux from the volcanic plume indicate that it should contribute only a few percent to this atmospheric variability. A diurnal cycle within the lower boundary layer producing a turbulence-dominated mixed layer during the day and stable layers at night is consistent with the observed refractivity. 2016, The Author(s).
BibTeX:
@article{Wadge2016309,
  author = {Wadge, G. and Costa, A. and Pascal, K. and Werner, C. and Webb, T.},
  title = {The Variability of Refractivity in the Atmospheric Boundary Layer of a Tropical Island Volcano Measured by Ground-Based Interferometric Radar},
  journal = {Boundary-Layer Meteorology},
  publisher = {Springer Netherlands},
  year = {2016},
  volume = {161},
  number = {2},
  pages = {309-333},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84975295232&doi=10.1007%2fs10546-016-0168-3&partnerID=40&md5=eca8644bfa4097cfd2104b90e44a7be6},
  doi = {10.1007/s10546-016-0168-3}
}
Wegmüller U, Santoro M and Werner C (2016), "Time-series analysis of Sentinel-1 interferometric wide swath data: Techniques and challenges", In European Space Agency, (Special Publication) ESA SP. Vol. SP-740 European Space Agency.
Abstract: Narrow directional scattering over agricultural fields can have severe implications for the confidence with which we assimilate satellite SAR data. So far directional scattering was investigated at like-polarization. Now, with ALOS PALSAR-2 and Sentinel-1 cross-polarized backscatter data are becoming much more widely available, and so directional scattering effects at cross-polarization should also be investigated, characterized and modeled. Split-beam techniques applied to dual-polarization PALSAR-2 clearly reveal that strong narrow directional scattering over agricultural fields is also present at cross-polarization - and this not only for fields with cultivation directions perpendicular to the line of sight, but also for fields with different cultivation directions. In our contribution we confirm the presence of strong directional scattering over some agricultural fields at L-band cross-polarization. Furthermore, we present a methodology that permits to at least partly mitigate the directional scattering effects.
BibTeX:
@conference{Wegmuller2016,
  author = {Wegmüller, U. and Santoro, M. and Werner, C.},
  editor = {Ouwehand L.},
  title = {Time-series analysis of Sentinel-1 interferometric wide swath data: Techniques and challenges},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2016},
  volume = {SP-740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988472332&partnerID=40&md5=7fcb1b4324e6e18eaaf6e6f140a65cb4}
}
Wegmüller U, Werner C, Strozzi T, Wiesmann A, Frey O and Santoro M (2016), "Sentinel-1 Support in the GAMMA Software", Procedia Computer Science. Vol. 100, pp. 1305-1312. Elsevier B.V..
Abstract: First results using the new Sentinel-1 SAR look very promising but the special interferometric wide-swath data acquired in the TOPS mode makes InSAR processing more challenging than for normal stripmap mode data. The steep azimuth spectra ramp in each burst results in very stringent co-registration requirements. Combining the data of the individual bursts and sub-swaths into consistent mosaics requires careful "book-keeping" in the handling of the data and meta data and the large file sizes and high data throughputs require also a good performance. Considering these challenges good support from software is getting increasingly important. In this contribution we describe the Sentinel-1 support in the GAMMA Software, a high-level software package used by researchers, service providers and operational users in their SAR, InSAR, PSI and offset tracking work. 2016 The Authors.
BibTeX:
@article{Wegmuller20161305,
  author = {Wegmüller, U. and Werner, C. and Strozzi, T. and Wiesmann, A. and Frey, O. and Santoro, M.},
  editor = {Martinho R., Rijo R., Cruz-Cunha M.M., Bjorn-Andersen N., Quintela Varajao J.E.},
  title = {Sentinel-1 Support in the GAMMA Software},
  journal = {Procedia Computer Science},
  publisher = {Elsevier B.V.},
  year = {2016},
  volume = {100},
  pages = {1305-1312},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006945250&doi=10.1016%2fj.procs.2016.09.246&partnerID=40&md5=6d1da67b1279d4426adced034b3bb23d},
  doi = {10.1016/j.procs.2016.09.246}
}
Wegmüller U, Werner C, Wiesmann A, Strozzi T, Kourkouli P and Frey O (2016), "Time-series analysis of Sentinel-1 interferometric wide swath data: Techniques and challenges", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 3898-3901. Institute of Electrical and Electronics Engineers Inc..
Abstract: Sentinel-1 IWS interferometric time-series analysis (SBAS and PSI) is discussed and results over Mexico City, a mega-city subject to very substantial ground deformation, are presented. In the early steps the processing needs to be adapted to the organization of the data in sub-swaths and burst, and for the SLC co-registration an extremely accurate co-registration is required for interferometry, because of the strong along-track Doppler centroid variation. Furthermore, a deramping of the co-registered SLC for an along-track phase ramp present in each burst is applied. After that interferometric time-series techniques (SBAS, PSI) can be applied in the same way as for stripmap mode data.
BibTeX:
@conference{Wegmuller20163898,
  author = {Wegmüller, U. and Werner, C. and Wiesmann, A. and Strozzi, T. and Kourkouli, P. and Frey, O.},
  title = {Time-series analysis of Sentinel-1 interferometric wide swath data: Techniques and challenges},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {3898-3901},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007440007&doi=10.1109%2fIGARSS.2016.7730012&partnerID=40&md5=5f6d0f3fc2df514e7690f53c106ce56c},
  doi = {10.1109/IGARSS.2016.7730012}
}
Werner C, Lowry B, Wegmüller U, Pugh N, Schrock G and Zhou W (2016), "Deformation time-series derived from terrestrial radar observations using persistent scatterer interferometry in Seattle, Washington", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2016-November, pp. 6835-6838. Institute of Electrical and Electronics Engineers Inc..
Abstract: The GPRI2 Ground-Based Real-Aperture radar was deployed in Seattle over a 6-week period during March and April 2015 to measure sub-millimeter scale subsidence related to construction of the Alaskan Way Viaduct and Seawall Replacement Program (AWVSRP). The radar was located on the mid-level roof of the Smith Tower overlooking Pioneer Square at an altitude of about 75 meters above street level. Radar images at 2 hour intervals were processed to obtain Line-of-Sight (LOS) deformation maps. Point target analysis was used to identify stable targets and to mitigate variations in propagation path length due to atmospheric changes. Geolocation and rectification of the more than 100,000 monitored points was carried out using a LiDAR DEM. 2016 IEEE.
BibTeX:
@conference{Werner20166835,
  author = {Werner, C. and Lowry, B. and Wegmüller, U. and Pugh, N. and Schrock, G. and Zhou, W.},
  title = {Deformation time-series derived from terrestrial radar observations using persistent scatterer interferometry in Seattle, Washington},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2016},
  volume = {2016-November},
  pages = {6835-6838},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007448331&doi=10.1109%2fIGARSS.2016.7730784&partnerID=40&md5=65eca0330d5c29e361f59d3378a105b7},
  doi = {10.1109/IGARSS.2016.7730784}
}
Askne J and Santoro M (2015), "On the estimation of boreal forest biomass from TanDEM-X data without training samples", IEEE Geoscience and Remote Sensing Letters. Vol. 12(4), pp. 771-775. Institute of Electrical and Electronics Engineers Inc..
Abstract: Boreal forests play an important part in the climate system, and estimates of the biomass are important also from an economic point of view. In this letter, forest aboveground biomass is estimated from bistatic TanDEM-X data, a Lidar digital elevation model (DEM), and the interferometric water cloud model, without using training samples to calibrate the model. The forest was characterized by allometric relations for area fill (vegetation fraction) and height versus stem volume, and stem volume versus biomass. Biomass was estimated for 202 forest stands at least 1 ha large at the forest test site of Remningstorp, Sweden, from 18 bistatic TanDEM-X acquisitions with a relative root-mean-square error (RMSE) of 16%-32%. TanDEM-X acquisitions with a height of ambiguity around 80 m resulted in the best results. A multitemporal combination resulted in a relative RMSE of 17%. This result is comparable with the retrieval error obtained in a previous study when training the model using a set of known forest stands. 2004-2012 IEEE.
BibTeX:
@article{Askne2015771,
  author = {Askne, J.I.H. and Santoro, M.},
  title = {On the estimation of boreal forest biomass from TanDEM-X data without training samples},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {12},
  number = {4},
  pages = {771-775},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84910038278&doi=10.1109%2fLGRS.2014.2361393&partnerID=40&md5=e125da9c0cc54fb5c65b479d66242d61},
  doi = {10.1109/LGRS.2014.2361393}
}
Barboux C, Strozzi T, Delaloye R, Wegmüller U and Collet C (2015), "Mapping slope movements in Alpine environments using TerraSAR-X interferometric methods", ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 109, pp. 178-192. Elsevier B.V..
Abstract: Mapping slope movements in Alpine environments is an increasingly important task in the context of climate change and natural hazard management. We propose the detection, mapping and inventorying of slope movements using different interferometric methods based on TerraSAR-X satellite images. Differential SAR interferograms (DInSAR), Persistent Scatterer Interferometry (PSI), Short-Baseline Interferometry (SBAS) and a semi-automated texture image analysis are presented and compared in order to determine their contribution for the automatic detection and mapping of slope movements of various velocity rates encountered in Alpine environments. Investigations are conducted in a study region of about 6 km × 6 km located in the Western Swiss Alps using a unique large data set of 140 DInSAR scenes computed from 51 summer TerraSAR-X (TSX) acquisitions from 2008 to 2012. We found that PSI is able to precisely detect only points moving with velocities below 3.5 cm/yr in the LOS, with a root mean squared error of about 0.58 cm/yr compared to DGPS records. SBAS employed with 11 days summer interferograms increases the range of detectable movements to rates up to 35 cm/yr in the LOS with a root mean squared error of 6.36. cm/yr, but inaccurate measurements due to phase unwrapping are already possible for velocity rates larger than 20 cm/year. With the semi-automated texture image analysis the rough estimation of the velocity rates over an outlined moving zone is accurate for rates of "cm/day", "dm/month" and "cm/month", but due to the decorrelation of yearly TSX interferograms this method fails for the observation of slow movements in the "cm/yr" range. 2015 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
BibTeX:
@article{Barboux2015178,
  author = {Barboux, C. and Strozzi, T. and Delaloye, R. and Wegmüller, U. and Collet, C.},
  title = {Mapping slope movements in Alpine environments using TerraSAR-X interferometric methods},
  journal = {ISPRS Journal of Photogrammetry and Remote Sensing},
  publisher = {Elsevier B.V.},
  year = {2015},
  volume = {109},
  pages = {178-192},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943803045&doi=10.1016%2fj.isprsjprs.2015.09.010&partnerID=40&md5=94317cf9932ae7553f4de3d6d2a72a6c},
  doi = {10.1016/j.isprsjprs.2015.09.010}
}
Beck I, Ludwig R, Bernier M, Strozzi T and Boike J (2015), "Vertical movements of frost mounds in subarctic permafrost regions analyzed using geodetic survey and satellite interferometry", Earth Surface Dynamics. Vol. 3(3), pp. 409-421. Copernicus GmbH.
Abstract: Permafrost-affected soils cover about 40-45 % of Canada. The environment in such areas, especially those located within the discontinuous permafrost zone, has been impacted more than any other by recorded climatic changes. A number of changes, such as surface subsidence and the degradation of frost mounds due to permafrost thawing, have already been observed at many locations. We surveyed three frost mounds (lithalsas) in the subarctic, close to Umiujaq in northern Quebec, using high-precision differential global positioning system (d-GPS) technology during field visits in 2009, 2010 and 2011, thus obtaining detailed information on their responses to the freezing and thawing that occur during the course of the annual temperature cycle. Seasonal pulsations were detected in the frost mounds, and these responses were shown to vary with their state of degradation and the land cover. The most degraded lithalsa showed a maximum amplitude of vertical movement (either up or down) between winter (freezing) and summer (thawing) of 0.19 ± 0.09 m over the study period, while for the least degraded lithalsa this figure was far greater (1.24 ± 0.47 m). Records from areas with little or no vegetation showed far less average vertical movement over the study period (0.17 ± 0.03 m) than those with prostrate shrubs (0.56 ± 0.02 m), suggesting an influence from the land cover. A differential interferometric synthetic aperture radar (D-InSAR) analysis was also completed over the lithalsas using selected TerraSAR-X images acquired from April to October 2009 and from March to October 2010, with a repeat cycle of 11 days. Interferograms with baselines shorter than 200 m were computed revealing a generally very low interferometric coherence, restricting the quantification of vertical movements of the lithalsas. Vertical surface movements of the order of a few centimeters were recorded in the vicinity of Umiujaq. 2014 Author(s).
BibTeX:
@article{Beck2015409,
  author = {Beck, I. and Ludwig, R. and Bernier, M. and Strozzi, T. and Boike, J.},
  title = {Vertical movements of frost mounds in subarctic permafrost regions analyzed using geodetic survey and satellite interferometry},
  journal = {Earth Surface Dynamics},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {3},
  number = {3},
  pages = {409-421},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941358363&doi=10.5194%2fesurf-3-409-2015&partnerID=40&md5=269642d02b500ed3b5472185064835af},
  doi = {10.5194/esurf-3-409-2015}
}
Bontemps S, Boettcher M, Brockmann C, Kirches G, Lamarche C, Radoux J, Santoro M, Van Bogaert E, Wegmüller U, Herold M, Achard F, Ramoino F, Arino O and Defourny P (2015), "Multi-year global land cover mapping at 300 M and characterization for climate modelling: Achievements of the land cover component of the ESA climate change initiative", In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives. Vol. 40,7W3, pp. 323-328. International Society for Photogrammetry and Remote Sensing.
Abstract: Essential Climate Variables were listed by the Global Climate Observing System as critical information to further understand the climate system and support climate modelling. The European Space Agency launched its Climate Change Initiative in order to provide an adequate response to the set of requirements for long-term satellite-based products for climate. Within this program, the CCI Land Cover project aims at revisiting all algorithms required for the generation of global land cover products that are stable and consistent over time, while also reflecting the land surface seasonality. To this end, the land cover concept is revisited to deliver a set of three consistent global land cover products corresponding to the 1998-2002, 2003-2007 and 2008-2012 periods, along with climatological 7-day time series representing the average seasonal dynamics of the land surface over the 1998-2012 period. The full Envisat MERIS archive (2003-2012) is used as main Earth Observation dataset to derive the 300-m global land cover maps, complemented with SPOT-Vegetation time series between 1998 and 2012. Finally, a 300-m global map of open permanent water bodies is derived from the 2005-2010 archive of the Envisat Advanced SAR imagery mainly acquired in the 150m Wide Swath Mode.
BibTeX:
@conference{Bontemps2015323,
  author = {Bontemps, S. and Boettcher, M. and Brockmann, C. and Kirches, G. and Lamarche, C. and Radoux, J. and Santoro, M. and Van Bogaert, E. and Wegmüller, U. and Herold, M. and Achard, F. and Ramoino, F. and Arino, O. and Defourny, P.},
  editor = {Schreier G., Skrovseth P.E., Staudenrausch H.},
  title = {Multi-year global land cover mapping at 300 M and characterization for climate modelling: Achievements of the land cover component of the ESA climate change initiative},
  booktitle = {International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives},
  publisher = {International Society for Photogrammetry and Remote Sensing},
  year = {2015},
  volume = {40,7W3},
  pages = {323-328},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930409672&doi=10.5194%2fisprsarchives-XL-7-W3-323-2015&partnerID=40&md5=88bf9713f0b1df36b8355223bedd9dff},
  doi = {10.5194/isprsarchives-XL-7-W3-323-2015}
}
Caduff R, Schlunegger F, Kos A and Wiesmann A (2015), "A review of terrestrial radar interferometry for measuring surface change in the geosciences", Earth Surface Processes and Landforms. Vol. 40(2), pp. 208-228. John Wiley and Sons Ltd.
Abstract: This paper presents a review of the current state of the art in the use of terrestrial radar interferometry for the detection of surface changes related to mass movement. Different hardware-types and acquisition concepts are described, which use either real or synthetic aperture for radar image formation. We present approaches for data processing procedures, paying special attention to the separation of high resolution displacement information from atmospheric phase variations. Recent case studies are used to illustrate applications in terrestrial radar interferometry for change detection. Applications range from detection and quantification of very slow moving (millimeters to centimeters per year) displacements in rock walls from repeat monitoring, to rapid processes resulting in fast displacements ( 50m/yr) acquired during single measurement campaigns with durations of only a few hours. Fast and episodic acting processes such as rockfall and snow avalanches can be assessed qualitatively in the spatial domain by mapping decorrelation caused by those processes. A concluding guide to best practice outlines the necessary preconditions that have to be fulfilled for successful application of the technique, as well as in areas characterized by rapid decorrelation. Empirical data from a Ku-band sensor show the range of temporal decorrelation of different surfaces after more than two years for rock-surfaces and after a few seconds to minutes in vegetated areas during windy conditions. The examples show that the displacement field can be measured for landslides in dense grassland, ice surfaces on flowing glaciers and snowpack creep. 2014 John Wiley & Sons, Ltd.
BibTeX:
@article{Caduff2015208,
  author = {Caduff, R. and Schlunegger, F. and Kos, A. and Wiesmann, A.},
  title = {A review of terrestrial radar interferometry for measuring surface change in the geosciences},
  journal = {Earth Surface Processes and Landforms},
  publisher = {John Wiley and Sons Ltd},
  year = {2015},
  volume = {40},
  number = {2},
  pages = {208-228},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921486170&doi=10.1002%2fesp.3656&partnerID=40&md5=4b5dc407a2097098a4958d7feb1b174d},
  doi = {10.1002/esp.3656}
}
Caduff R, Wiesmann A, Buhler Y and Pielmeier C (2015), "Continuous monitoring of snowpack displacement at high spatial and temporal resolution with terrestrial radar interferometry", Geophysical Research Letters. Vol. 42(3), pp. 813-820. Blackwell Publishing Ltd.
Abstract: Terrestrial radar interferometry is used in geotechnical applications for monitoring hazardous Earth or rock movements. In this study, we use it to continuously monitor snowpack displacements. As test site, the Dorfberg slope at Davos, Switzerland, was measured continuously during March 2014. The line of sight displacement was retrieved at a spatial resolution of millimeter to centimeter and a temporal resolution of up to 1min independent of visibility. The results reveal several temperature-driven diurnal acceleration and deceleration cycles. The initiation of a small full-depth glide avalanche was observed after 50cm total differential displacement. The maximum measured displacement of another differential glide area reached 43cm/h without resulting in a full-depth avalanche even after a total measured differential displacement of 4.5m. In regard of the difficulty to predict full-depth glide avalanches on the regional scale, the presented method has big potential for operational snow glide monitoring on critical slopes. 2015 The Authors.
BibTeX:
@article{Caduff2015813,
  author = {Caduff, R. and Wiesmann, A. and Buhler, Y. and Pielmeier, C.},
  title = {Continuous monitoring of snowpack displacement at high spatial and temporal resolution with terrestrial radar interferometry},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2015},
  volume = {42},
  number = {3},
  pages = {813-820},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925161852&doi=10.1002%2f2014GL062442&partnerID=40&md5=26950fea50190b5888ad5d1202f208ab},
  doi = {10.1002/2014GL062442}
}
Casu F, Manconi A, Elefante S and Zinno I (2015), "Surface displacement time series retrieved by fully exploiting space-borne SAR data", Engineering Geology for Society and Territory - Volume 2: Landslide Processes. , pp. 417-420. Springer International Publishing.
Abstract: We present two applications of a novel approach to analyze surface deformation in areas experiencing large and/or rapid surface displacements. We show how the joint consideration of the phase and amplitude information of a space-borne Synthetic Aperture Radar (SAR) dataset can be used to better describe the near-field and the far-field characteristics of the surface deformation. This methodology has potential applications in the analysis of surface deformation phenomena relevant to natural hazards and/or anthropic activities. The consideration of this approach on SAR data acquired by high resolution and short revisit time satellites opens new scenarios in the use of SAR data to monitor the Earth’s crust. . Springer International Publishing Switzerland 2015.
BibTeX:
@book{Casu2015417,
  author = {Casu, F. and Manconi, A. and Elefante, S. and Zinno, I.},
  title = {Surface displacement time series retrieved by fully exploiting space-borne SAR data},
  journal = {Engineering Geology for Society and Territory - Volume 2: Landslide Processes},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {417-420},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944539859&doi=10.1007%2f978-3-319-09057-3_66&partnerID=40&md5=6c463e1ffa3abbc8a68686ad77d17b6b},
  doi = {10.1007/978-3-319-09057-3_66}
}
Cossu F, Hocke K, Martynov A, Martius O and Matzler C (2015), "Atmospheric water parameters measured by a ground-based microwave radiometer and compared with the WRF model", Atmospheric Science Letters. Vol. 16(4), pp. 465-472. John Wiley and Sons Ltd.
Abstract: The microwave radiometer TROWARA measures integrated water vapour (IWV) and integrated cloud liquid water (ILW) at Bern since 1994 with a time resolution of 7s. In this study, we compare TROWARA measurements with a simulation of summer 2012 in Switzerland performed with the Weather Research and Forecasting (WRF) model. It is found that the WRF model agrees very well with TROWARA's IWV variations with a mean bias of only 0.7mm. The ILW distribution of the WRF model, although similar in shape to TROWARA's distribution, overestimates the fraction of clear sky periods (83% compared to 60%). 2015 Royal Meteorological Society.
BibTeX:
@article{Cossu2015465,
  author = {Cossu, F. and Hocke, K. and Martynov, A. and Martius, O. and Matzler, C.},
  title = {Atmospheric water parameters measured by a ground-based microwave radiometer and compared with the WRF model},
  journal = {Atmospheric Science Letters},
  publisher = {John Wiley and Sons Ltd},
  year = {2015},
  volume = {16},
  number = {4},
  pages = {465-472},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944441077&doi=10.1002%2fasl.583&partnerID=40&md5=4e10398846ad8b734b0454974e84ceea},
  doi = {10.1002/asl.583}
}
Cossu F, Hocke K and Matzler C (2015), "A 10-year cloud fraction climatology of liquid water clouds over Bern observed by a ground-based microwave radiometer", Remote Sensing. Vol. 7(6), pp. 7768-7784. MDPI AG.
Abstract: Cloud fraction (CF) is known as the dominant modulator of Earth's radiative fluxes. Ground-based CF observations are useful to characterize the cloudiness of a specific site and are valuable for comparison with satellite observations and numerical models. We present for the first time CF statistics (relative to liquid clouds only) for Bern, Switzerland, derived from the observations of a ground-based microwave radiometer. CF is derived with a new method involving the analysis of the integrated liquid water distribution measured by the radiometer. The 10-year analyzed period (2004-2013) allowed us to compute a CF climatology for Bern, showing a maximum CF of 60.9% in winter and a minimum CF of 42.0% in summer. The CF monthly anomalies are identified with respect to the climatological mean values, and they are confirmed through MeteoSwiss yearly climatological bulletins. The CF monthly mean variations are similar to the observations taken at another Swiss location, Payerne, suggesting a large-scale correlation between different sites on the Swiss Plateau. A CF diurnal cycle is also computed, and large intraseasonal variations are found. The overall mean CF diurnal cycle, however, shows a typical sinusoidal cycle, with higher values in the morning and lower values in the afternoon. 2015 by the authors.
BibTeX:
@article{Cossu20157768,
  author = {Cossu, F. and Hocke, K. and Matzler, C.},
  title = {A 10-year cloud fraction climatology of liquid water clouds over Bern observed by a ground-based microwave radiometer},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2015},
  volume = {7},
  number = {6},
  pages = {7768-7784},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84933544292&doi=10.3390%2frs70607768&partnerID=40&md5=642cd3efd8f43b09baa0a6243912527b},
  doi = {10.3390/rs70607768}
}
Facello A, Giordan D and Manconi A (2015), "Analysis of snow cover in landslide prone areas: The example of Tena Valley, Central Pyrenees, Spain", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 766-769. Institute of Electrical and Electronics Engineers Inc..
Abstract: In this work, we analyze the characteristics of snow cover using two space borne products (Level 1C and Level 2A) provided by the SPOT4 Take 5 Initiative. The principal aim of this initiative is to evaluate the benefits of Sentinel 2 acquisition mode before its launch. We processed SPOT4 images acquired from February 2013 to June 2013 over the site of Midi-Pyrénées (South West). The Normalized Difference Snow Index (NDSI) and Fraction of Snow Cover (SCF) are calculated on all dataset and the snow surface map and its evolution over the time is obtained. The distribution of snow cover is slightly larger using the Level 1C than in the Level 2A data. This information will be merged with climatic data and snow depth ground measures in order to derive the melt rate, the snow cover depletion rate and the snow water equivalent, and to analyze the groundwater level variations and their interaction with the landslide activity. 2015 IEEE.
BibTeX:
@conference{Facello2015766,
  author = {Facello, A. and Giordan, D. and Manconi, A.},
  title = {Analysis of snow cover in landslide prone areas: The example of Tena Valley, Central Pyrenees, Spain},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {766-769},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962595677&doi=10.1109%2fIGARSS.2015.7325877&partnerID=40&md5=0dc2bb26f9571cfbee6319822a919d5c},
  doi = {10.1109/IGARSS.2015.7325877}
}
Fernandez-Moran R, Wigneron J-P, Lopez-Baeza E, Al-Yaari A, Coll-Pajaron A, Mialon A, Miernecki M, Parrens M, Salgado-Hernanz P, Schwank M, Wang S and Kerr Y (2015), "Roughness and vegetation parameterizations at L-band for soil moisture retrievals over a vineyard field", Remote Sensing of Environment. Vol. 170, pp. 269-279. Elsevier Inc..
Abstract: The capability of L-band radiometry to monitor surface soil moisture (SM) at global scale has been analyzed in numerous studies, mostly in the framework of the ESA SMOS and NASA SMAP missions. To retrieve SM from L-band radiometric observations, two significant effects have to be accounted for, namely soil roughness and vegetation optical depth. In this study, soil roughness effects on retrieved SM valueswere evaluated using brightness temperatures acquired by the L-band ELBARA-II radiometer, over a vineyard field at the Valencia Anchor Station (VAS) site during the year 2013. Different combinations of the values of themodel parameters used to account for soil roughness effects (HR, QR, NRH and NRV) in the L-MEB model were evaluated. The L-MEB model (L-band Microwave Emission of the Biosphere) is the forward radiative transfer model used in the SMOS soil moisture retrieval algorithm. In this model, HR parameterizes the intensity of roughness effects, QR accounts for polarization effects, and NRH and NRV parameterize the variations of the soil reflectivity as a function of the observation angle, θ, respectively for both H (Horizontal) and V (Vertical) polarizations. These evaluationswere made by comparing in-situ measurements of SM (used here as a reference) against SM retrievals derived from tower-based ELBARAII brightness temperatures mentioned above. The general retrieval approach consists of the inversion of L-MEB. Two specific configurations were tested: the classical 2-Parameter (2-P) retrieval configuration where SM and τNAD (vegetation optical depth at nadir) are retrieved, and a 3-Parameter (3-P) configuration, accounting for the additional effects of the vineyard vegetation structure. Using the 2-P configuration, it was found that setting NRp (p = H or V) equals to -1 provided the best SM estimations in terms of correlation and unbiased Root Mean Square Error (ubRMSE). The assumption NRV = NRH = -1 simplifies the L-MEB retrieval, since the two parameters τNAD and HR can then be grouped and retrieved as a single parameter (method here defined as the Simplified Retrieval Method (SRP)). The main advantage of the SRP method is that it is not necessary to calibrate HR before performing the SM retrievals. Using the 3-P configuration, the results improved, with respect to SM retrievals, in terms of correlation and ubRMSE, as the structural characteristics of the vineyards were better accounted for. However, this method still requires the calibration of HR, a disadvantage for operational applications. Finally, it was found that the use of in-situ roughness measurements to calibrate the roughness model parameters did not provide significant improvements in the SM retrievals as compared to the SRP method. 2015 Elsevier Inc.
BibTeX:
@article{Fernandez-Moran2015269,
  author = {Fernandez-Moran, R. and Wigneron, J.-P. and Lopez-Baeza, E. and Al-Yaari, A. and Coll-Pajaron, A. and Mialon, A. and Miernecki, M. and Parrens, M. and Salgado-Hernanz, P.M. and Schwank, M. and Wang, S. and Kerr, Y.H.},
  title = {Roughness and vegetation parameterizations at L-band for soil moisture retrievals over a vineyard field},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {170},
  pages = {269-279},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943618524&doi=10.1016%2fj.rse.2015.09.006&partnerID=40&md5=e73e752d40c06aa4131fc6a9a93ea4c3},
  doi = {10.1016/j.rse.2015.09.006}
}
Fernandez-Moran R, Wigneron J-P, Lopez-Baeza E, Miernecki M, Salgado-Hernanz P, Coll M, Kerr Y and Schwank M (2015), "Towards a long-term dataset of ELBARA-II measurements assisting SMOS level-3 land product and algorithm validation at the Valencia Anchor Station [Validación a largo plazo de datos de nivel 3 de tierra de SMOS con medidas de ELBARA-II en la Valencia Anchor Station]", Revista de Teledeteccion. Vol. 2015(43), pp. 55-62. Asociacion Espanola de Teledeteccion.
Abstract: The Soil Moisture and Ocean Salinity (SMOS) mission was launched on 2nd November 2009 with the objective of providing global estimations of soil moisture and sea salinity. The main activity of the Valencia Anchor Station (VAS) is currently to assist in a long-term validation of SMOS land products. This study focus on a level 3 SMOS data validation with in situ measurements carried out in the period 2010-2012 over the VAS. ELBARA-II radiometer is placed in the VAS area, observing a vineyard field considered as representative of a major proportion of an area of 50×50 km, enough to cover a SMOS footprint. Brightness temperatures (TB) acquired by ELBARA-II have been compared to those observed by SMOS at the same dates and time. They were also used for the L-MEB model inversion to retrieve soil moisture (SM), which later on have been compared to those provided by SMOS as level 3 data. A good correlation between both TB datasets was found, improving year by year, mainly due to the decrease of precipitations in the analyzed period and the mitigation of radio frequency interferences at L-band. The larger homogeneity of the radiometer footprint as compared to SMOS explains the higher variability of its TB. Periods of more intense precipitation (spring and autumn) also presented higher SM, which corroborates the consistency of SM retrieved from ELBARA-II’s observations. However, the results show that SMOS level 3 data underestimate SM as compared to ELBARA-II’s, probably due to the influence of the small soil fraction which is not cultivated in vineyards. SMOS estimations in descending orbit (6 pm) had better quality (higher correlation, lower RMSE and bias) than the ones in ascending orbit (6 am, when there is a higher soil moisture). 2015, Asociacion Espanola de Teledeteccion. All rights reserved.
BibTeX:
@article{Fernandez-Moran201555,
  author = {Fernandez-Moran, R. and Wigneron, J.-P. and Lopez-Baeza, E. and Miernecki, M. and Salgado-Hernanz, P. and Coll, M.A. and Kerr, Y.H. and Schwank, M.},
  title = {Towards a long-term dataset of ELBARA-II measurements assisting SMOS level-3 land product and algorithm validation at the Valencia Anchor Station [Validación a largo plazo de datos de nivel 3 de tierra de SMOS con medidas de ELBARA-II en la Valencia Anchor Station]},
  journal = {Revista de Teledeteccion},
  publisher = {Asociacion Espanola de Teledeteccion},
  year = {2015},
  volume = {2015},
  number = {43},
  pages = {55-62},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84934767399&doi=10.4995%2fraet.2015.2297&partnerID=40&md5=52f3cce5aacf3b5790c310c4065e408f},
  doi = {10.4995/raet.2015.2297}
}
Frey O, Werner C, Schneebeli M, Macfarlane A and Wiesmann A (2015), "Enhancement of snowscat for tomographic observation capabilities", In European Space Agency, (Special Publication) ESA SP. Vol. SP-731 European Space Agency.
Abstract: The SnowScat device, a tower-mounted fully polarimetric scatterometer for measurements of the radar crosssection of snow at X-band up to Ku-band, has recently been enhanced to also support a tomographic profiling mode. The new tomographic profiling capability of SnowScat allows for performing high-resolution observations providing further insights into the complex electromagnetic interaction within snowpacks. In this paper, we present first results obtained from a series of tomographic profiles of a snowpack acquired with the enhanced SnowScat device at a test site of SLF in Davos, Switzerland, between Dec. 2014 and March 2015.
BibTeX:
@conference{Frey2015,
  author = {Frey, O. and Werner, C.L. and Schneebeli, M. and Macfarlane, A. and Wiesmann, A.},
  editor = {Ouwehand L.},
  title = {Enhancement of snowscat for tomographic observation capabilities},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2015},
  volume = {SP-731},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961821223&partnerID=40&md5=42e5855174f0f286cfac3a5ee59fd4ac}
}
Frey O, Werner C and Wiesmann A (2015), "Tomographic profiling of the structure of a snow pack at X-/Ku-Band using SnowScat in SAR mode", In 2015 European Radar Conference, EuRAD 2015 - Proceedings. , pp. 21-24. Institute of Electrical and Electronics Engineers Inc..
Abstract: The SnowScat device, a fully-polarimetric scatterometer originally designed to measure the radar cross-section of snow at a frequency range from 9.2 to 17.8 GHz (X-band to Ku-band), has recently been extended towards a high-resolution tomographic measurement mode. Such tomographic profiling observations provide further insights into the complex electromagnetic interaction within snowpacks, e.g., by revealing different layers, such as melt-freeze crusts, inside the snowpack. In this contribution, we report first results from an initial tomographic measurement campaign carried out at a test site in Davos, Switzerland, in winter 2014/2015. 2015 EuMA.
BibTeX:
@conference{Frey201521,
  author = {Frey, O. and Werner, C.L. and Wiesmann, A.},
  title = {Tomographic profiling of the structure of a snow pack at X-/Ku-Band using SnowScat in SAR mode},
  booktitle = {2015 European Radar Conference, EuRAD 2015 - Proceedings},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  pages = {21-24},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962891385&doi=10.1109%2fEuRAD.2015.7346227&partnerID=40&md5=ba4b1b5df9daaa178a39251f90a02e37},
  doi = {10.1109/EuRAD.2015.7346227}
}
Giordan D, Manconi A, Allasia P and Bertolo D (2015), "Brief Communication: On the rapid and efficient monitoring results dissemination in landslide emergency scenarios: The Mont de la Saxe case study", Natural Hazards and Earth System Sciences. Vol. 15(9), pp. 2009-2017. Copernicus GmbH.
Abstract: Straightforward communication of monitoring results is of major importance in emergency scenarios relevant to large slope instabilities. Here we describe the communication strategy developed for the Mont de La Saxe rockslide threatening La Palud and Entrèves hamlets in the Courmayeur municipality (Aosta Valley, Italy). Starting from the definition of actions and needs of the landslide management team, including scientists, technicians, civil protection operators, decision makers, and politicians, we show that sharing and disseminating ad hoc information simplifies the understanding of the landslide evolution, as well as the correct communication of the level of criticality. 2015 Author(s).
BibTeX:
@article{Giordan20152009,
  author = {Giordan, D. and Manconi, A. and Allasia, P. and Bertolo, D.},
  title = {Brief Communication: On the rapid and efficient monitoring results dissemination in landslide emergency scenarios: The Mont de la Saxe case study},
  journal = {Natural Hazards and Earth System Sciences},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {15},
  number = {9},
  pages = {2009-2017},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941194236&doi=10.5194%2fnhess-15-2009-2015&partnerID=40&md5=c8f30fe96e750b703c1cd9915c88688e},
  doi = {10.5194/nhess-15-2009-2015}
}
Giordan D, Manconi A, Facello A, Baldo M, Dell'Anese F, Allasia P and Dutto F (2015), "Brief Communication: The use of an unmanned aerial vehicle in a rockfall emergency scenario", Natural Hazards and Earth System Sciences. Vol. 15(1), pp. 163-169. Copernicus GmbH.
Abstract: In recent years, the use of unmanned aerial vehicles (UAVs) in civilian/commercial contexts are becoming increasingly common, as well as for applications concerning anthropic and natural disasters. In this paper, we present the first results of a research project aimed at defining a possible methodology for the use of micro-UAVs in emergency scenarios relevant to rockfall phenomena. To develop and support the method presented herein, the results relevant to a rockfall emergency occurred on 7 March 2014 in the San Germano municipality (north-western Italy) are presented and discussed.
BibTeX:
@article{Giordan2015163,
  author = {Giordan, D. and Manconi, A. and Facello, A. and Baldo, M. and Dell'Anese, F. and Allasia, P. and Dutto, F.},
  title = {Brief Communication: The use of an unmanned aerial vehicle in a rockfall emergency scenario},
  journal = {Natural Hazards and Earth System Sciences},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {15},
  number = {1},
  pages = {163-169},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921914600&doi=10.5194%2fnhess-15-163-2015&partnerID=40&md5=481902691c4dff76bd799ebf0e42590d},
  doi = {10.5194/nhess-15-163-2015}
}
Giordan D, Manconi A, Tannant D and Allasia P (2015), "UAV: Low-cost remote sensing for high-resolution investigation of landslides", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 5344-5347. Institute of Electrical and Electronics Engineers Inc..
Abstract: The civilian use of small inexpensive mini- and micro-UAVs has increased dramatically in the past few years. UAVs can be used for natural hazards management. In this context, UAVs can be very useful for surveying and monitoring of active small landslides in urban environments. In this paper, a methodology for the data acquisition and processing that considers the landslide typology is presented and discussed. Two case studies from the northwest part of Italy are also described to illustrate the presented methodology. 2015 IEEE.
BibTeX:
@conference{Giordan20155344,
  author = {Giordan, D. and Manconi, A. and Tannant, D.D. and Allasia, P.},
  title = {UAV: Low-cost remote sensing for high-resolution investigation of landslides},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {5344-5347},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962567735&doi=10.1109%2fIGARSS.2015.7327042&partnerID=40&md5=2cca1ef8dbf560c480d2dc0eebc8e375},
  doi = {10.1109/IGARSS.2015.7327042}
}
Hanssen R, Van Leijen F, Pierdicca N, Floury N and Wegmüller U (2015), "L-band multistatic radar interferometry for 3D deformation vector decomposition", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 4057-4060. Institute of Electrical and Electronics Engineers Inc..
Abstract: SAOCOM is an Argentinian L band system formed by two satellites (SAOCOM-1A and SAOCOM-1B). ESA is investigating the possible applications of a companion satellite (SAOCOM-CS) carrying a passive receiver working in concert with one of the SAOCOM-1 satellites. During the mission there will be cycles with a long along-track bistatic baseline, suitable for deformation monitoring. Together with the combination of ascending and descending orbits, this geometry will produce four measurements from different viewing geometries, enabling us to estimate the 3D motion vector. Here we investigate the sensitivity of such a configuration, and the opportunities for increasing the density of persistent scatterers. 2015 IEEE.
BibTeX:
@conference{Hanssen20154057,
  author = {Hanssen, R.F. and Van Leijen, F. and Pierdicca, N. and Floury, N. and Wegmüller, U.},
  title = {L-band multistatic radar interferometry for 3D deformation vector decomposition},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {4057-4060},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962554178&doi=10.1109%2fIGARSS.2015.7326716&partnerID=40&md5=6f8af5a747337aa471fff8d20967d55d},
  doi = {10.1109/IGARSS.2015.7326716}
}
Hofmann D, Preuss G and Matzler C (2015), "Evidence for biological shaping of hair ice", Biogeosciences. Vol. 12(14), pp. 4261-4273. Copernicus GmbH.
Abstract: An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0°C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice-carrying wood. One species, Exidiopsis effusa (Ee), was present on all investigated samples. Both hair-ice-producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity, and that ice segregation is the common mechanism of ice growth on the wood surface. The fungus plays the role of shaping the ice hairs and preventing them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S) compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as being the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor. Author(s) 2015.
BibTeX:
@article{Hofmann20154261,
  author = {Hofmann, D. and Preuss, G. and Matzler, C.},
  title = {Evidence for biological shaping of hair ice},
  journal = {Biogeosciences},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {12},
  number = {14},
  pages = {4261-4273},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937807540&doi=10.5194%2fbg-12-4261-2015&partnerID=40&md5=b0494ffc8b66a15cba3e1709f134da3b},
  doi = {10.5194/bg-12-4261-2015}
}
Jonard F, Weihermuller L, Schwank M, Jadoon K, Vereecken H and Lambot S (2015), "Estimation of Hydraulic properties of a sandy soil using ground-based active and passive microwave remote sensing", IEEE Transactions on Geoscience and Remote Sensing. Vol. 53(6), pp. 3095-3109. Institute of Electrical and Electronics Engineers Inc..
Abstract: In this paper, we experimentally analyzed the feasibility of estimating soil hydraulic properties from 1.4 GHz radiometer and 0.8-2.6 GHz ground-penetrating radar (GPR) data. Radiometer and GPR measurements were performed above a sand box, which was subjected to a series of vertical water content profiles in hydrostatic equilibrium with a water table located at different depths. A coherent radiative transfer model was used to simulate brightness temperatures measured with the radiometer. GPR data were modeled using full-wave layered medium Green's functions and an intrinsic antenna representation. These forward models were inverted to optimally match the corresponding passive and active microwave data. This allowed us to reconstruct the water content profiles, and thereby estimate the sand water retention curve described using the van Genuchten model. Uncertainty of the estimated hydraulic parameters was quantified using the Bayesian-based DREAM algorithm. For both radiometer and GPR methods, the results were in close agreement with in situ time-domain reflectometry (TDR) estimates. Compared with radiometer and TDR, much smaller confidence intervals were obtained for GPR, which was attributed to its relatively large bandwidth of operation, including frequencies smaller than 1.4 GHz. These results offer valuable insights into future potential and emerging challenges in the development of joint analyses of passive and active remote sensing data to retrieve effective soil hydraulic properties. 2015 IEEE.
BibTeX:
@article{Jonard20153095,
  author = {Jonard, F. and Weihermuller, L. and Schwank, M. and Jadoon, K.Z. and Vereecken, H. and Lambot, S.},
  title = {Estimation of Hydraulic properties of a sandy soil using ground-based active and passive microwave remote sensing},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {53},
  number = {6},
  pages = {3095-3109},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923192590&doi=10.1109%2fTGRS.2014.2368831&partnerID=40&md5=c5ede37c65797a49448594277201badc},
  doi = {10.1109/TGRS.2014.2368831}
}
Kadlecik P, Kajzar V, Nekvasilova Z, Wegmüller U and Dolezalova H (2015), "Evaluation of the subsidence based on dinsar and GPS measurements near Karvina, Czech Republic", Acta Universitatis Carolinae, Geographica. Vol. 50(1), pp. 51-61. Karolinum - Nakladatelstvi Univerzity Karlovy.
Abstract: The main impacts on the landscape due to coal mining in the Czech part of the Upper Silesian basin are ground subsidence and manmade landscape changes related to the mining. Two measurement techniques were used to determine the values of subsidence; these were then compared together to verify the results obtained. The first, differential SAR interferometry (dlnSAR), a remote sensing method, was applied by Gamma Remote Sensing in the frame of ESA GMES Project Terrafirma, using ALOS PALSAR data. The second was the GPS fast static method, which was provided by the Institute of Geonics AS CR. The GPS monitoring was established at a locality near Karviná in 2006. A comparison of the results is described on one subsidence depression created above a panel mined from February 2007 to May 2008. Aspects of the comparison applying to the subsidence measurements are discussed along with the advantages and disadvantages of both methods.
BibTeX:
@article{Kadlecik201551,
  author = {Kadlecik, P. and Kajzar, V. and Nekvasilova, Z. and Wegmüller, U. and Dolezalova, H.},
  title = {Evaluation of the subsidence based on dinsar and GPS measurements near Karvina, Czech Republic},
  journal = {Acta Universitatis Carolinae, Geographica},
  publisher = {Karolinum - Nakladatelstvi Univerzity Karlovy},
  year = {2015},
  volume = {50},
  number = {1},
  pages = {51-61},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84934326219&doi=10.14712%2f23361980.2015.86&partnerID=40&md5=4106f485376ed605317eaa9da57109fb},
  doi = {10.14712/23361980.2015.86}
}
Lanteri L, Bormioli D, Morelli M, Dutto F, Giordan D and Manconi A (2015), "Rockfall analysis during emergency scenarios", Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation. , pp. 711-714. Springer International Publishing.
Abstract: In this paper we describe a procedure for the study and management of rockfall affected areas. During the MASSA project, we defined a procedure for the management of the first emergency phase after the gravitational phenomenon, describing what it could be done for a first analysis and monitoring of the instable areas. In particular, the developed methodology considered three important aspects that should begin during the first 48-72 h: (i) preliminary morphological/structural analysis; (ii) detection and monitoring of instable areas during the emergency phase; (iii) communication strategies for the event management and divulgation to the population. Starting from the defined methodology, we also describe the first results of the application of this method to the Quincinetto rockfall test site, Piedmont, Italy. Springer International Publishing Switzerland 2015.
BibTeX:
@book{Lanteri2015711,
  author = {Lanteri, L. and Bormioli, D. and Morelli, M. and Dutto, F. and Giordan, D. and Manconi, A.},
  title = {Rockfall analysis during emergency scenarios},
  journal = {Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {711-714},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944607084&doi=10.1007%2f978-3-319-09048-1_138&partnerID=40&md5=61b0cd0a360ae347339a28aaa1226c5f},
  doi = {10.1007/978-3-319-09048-1_138}
}
Leinss S, Lemmetyinen J, Wiesmann A and Hajnsek I (2015), "Interferometric and polarimetric methods to determine SWE, fresh snow depth and the anisotropy of dry snow", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 4029-4032. Institute of Electrical and Electronics Engineers Inc..
Abstract: Dry snow can be considered as a transparent but refractive medium which causes a phase delay in the reflected signal of active radar remote sensing systems. Here, we analyze the phase delay to estimate Snow Water Equivalent (SWE), the depth of fresh snow and the anisotropic orientation of ice grains in the snow volume. SWE is determined from the integrated phase shift measured by differential interferometry. The temporal evolution of the snow anisotropy could be observed because different microwave polarizations show different propagation speeds in anisotropic snow. The depth of fresh snow as well as snow metamorphosis is discussed with respect to characteristic phase-shifts in the co-polar phase difference. Ground based radar observations from the Snow-scat instrument installed at a test site near Sodankyla, Finland, form the data basis for this paper. 2015 IEEE.
BibTeX:
@conference{Leinss20154029,
  author = {Leinss, S. and Lemmetyinen, J. and Wiesmann, A. and Hajnsek, I.},
  title = {Interferometric and polarimetric methods to determine SWE, fresh snow depth and the anisotropy of dry snow},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {4029-4032},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962509241&doi=10.1109%2fIGARSS.2015.7326709&partnerID=40&md5=0d239760445ede7e996980efe897bd1d},
  doi = {10.1109/IGARSS.2015.7326709}
}
Leinss S, Wiesmann A, Lemmetyinen J and Hajnsek I (2015), "Snow Water Equivalent of Dry Snow Measured by Differential Interferometry", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 8(8), pp. 3773-3790. Institute of Electrical and Electronics Engineers.
Abstract: Large scale mapping of snow water equivalent (SWE) is a long-lasting request in many scientific and economical fields. Active and passive microwave remote sensing methods are explored, as local methods cannot be generalized due to the spatial inhomogeneity of the snow pack. Microwaves interact with snow by absorption, scattering, and refraction. For dry snow of a few meters depth and frequencies below 20 GHz, absorption and scattering in the snow volume are negligible compared with the backscattered energy from the underlying ground. The signal delay caused by refraction can be measured with differential radar interferometry, but phase wrapping errors and temporal decorrelation must be considered. We demonstrate that large ΔSWE can be accurately determined from dense time series of differential interferograms at X- and Ku-band by temporal integration. Lost phase cycles are reconstructed with a two-frequency approach. Temporal decorrelation is minimized by a temporal resolution of 4h. A linear function between ΔSWE and phase difference is derived, which deviates only a few percent from the exact solution and which depends negligibly on snow density and stratigraphy. ΔSWE retrieved from observations of the SnowScat instrument (SSI) were validated against observed SWE from different reference instruments, installed at a test site near the town of Sodankyla, Finland. An accuracy below ±6 mm SWE was achieved at frequencies of 10 and 16 GHz for up to 200 mm of ΔSWE. An exceptionally high temporal coherence was observed for up to 30 days for dry snow, whereas for wet snow it decayed within hours. 2008-2012 IEEE.
BibTeX:
@article{Leinss20153773,
  author = {Leinss, S. and Wiesmann, A. and Lemmetyinen, J. and Hajnsek, I.},
  title = {Snow Water Equivalent of Dry Snow Measured by Differential Interferometry},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2015},
  volume = {8},
  number = {8},
  pages = {3773-3790},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027922593&doi=10.1109%2fJSTARS.2015.2432031&partnerID=40&md5=238ee8339c485a24b0b9ec08f08c57e0},
  doi = {10.1109/JSTARS.2015.2432031}
}
Lemmetyinen J, Schwank M, Rautiainen K, Kontu A, Parkkinen T, Matzler C, Wiesmann A, Wegmüller U, Derksen C, Toose P, Roy A and Pulliainen J (2015), "Potential of L-band passive microwave radiometry for snow parameter retrieval", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 4033-4036. Institute of Electrical and Electronics Engineers Inc..
Abstract: Dry snow is conventionally considered as having minimal effect on microwave radiation at long wavelengths (such as L-band). However, dry snow affects observed microwave signatures even at these wavelengths through changes in impedance matching between soil and the overlying media, as well as through changes in the refraction angle at the soil interface. Exploiting these effects, the multi-angular, dual-polarized L-band observations of e.g. the European Space Agency's SMOS (Soil Moisture and Ocean Salinity) mission have the potential to derive snow properties, such as the density of the lowest layers of the snowpack in contact with the ground. This in turn, would have the potential to inform retrieval schemes of snow cover based on EO-data from other sensors. In addition, the theoretical studies demonstrate that the effect of dry snow on retrieval of other geophysical variables, such as soil moisture, is not negligible. In this study, we demonstrate the simultaneous retrieval of snow density and ground permittivity in dry snow conditions, using a multi-year dataset of tower-based L-band observations. We show that following predictions of the theoretical studies, the retrieved snow density matches that of the density measured for the lowest snow layers; dry snow cover is also shown to affect retrievals of ground permittivity by up to 40 %. 2015 IEEE.
BibTeX:
@conference{Lemmetyinen20154033,
  author = {Lemmetyinen, J. and Schwank, M. and Rautiainen, K. and Kontu, A. and Parkkinen, T. and Matzler, C. and Wiesmann, A. and Wegmüller, U. and Derksen, C. and Toose, P. and Roy, A. and Pulliainen, J.},
  title = {Potential of L-band passive microwave radiometry for snow parameter retrieval},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {4033-4036},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962613692&doi=10.1109%2fIGARSS.2015.7326710&partnerID=40&md5=03d3c26c3cb5b39913cfe978bee66c31},
  doi = {10.1109/IGARSS.2015.7326710}
}
Lollino G, Manconi A, Clague J, Shan W and Chiarle M (2015), "Engineering geology for society and territory - Volume 1: Climate change and engineering geology", Engineering Geology for Society and Territory - Volume 1: Climate Change and Engineering Geology. , pp. 1-572. Springer International Publishing.
Abstract: This book is one out of 8 IAEG XII Congress volumes and deals with climate change affecting different natural processes and environments, such as slope dynamics, water courses, coastal and marine environments, hydrological and littoral processes and permafrost terrain. Due to climate change, major effects are also expected on territorial planning and infrastructure, particularly in extreme climate regions. The volume and its contents aim to analyze the role of engineering geology and the solutions it may offer with respect to the ongoing environmental changes. Contributions regard the modeling of both the factors and the effects induced by climate change. Potential impacts of the climate change on the common practice and routine work of engineering geologists are also analyzed, with particular attention to the risk assessment and mitigation procedures and to the adaptation measures adopted. The Engineering Geology for Society and Territory volumes of the IAEG XII Congress held in Torino from September 15-19, 2014, analyze the dynamic role of engineering geology in our changing world and build on the four main themes of the congress: environment, processes, issues and approaches. The congress topics and subject areas of the 8 IAEG XII Congress volumes are: Climate Change and Engineering Geology. Landslide Processes. River Basins, Reservoir Sedimentation and Water Resources. Marine and Coastal Processes. Urban Geology, Sustainable Planning and Landscape Exploitation. Applied Geology for Major Engineering Projects. Education, Professional Ethics and Public Recognition of Engineering Geology. Preservation of Cultural Heritage. Springer International Publishing Switzerland 2015.
BibTeX:
@book{Lollino20151a,
  author = {Lollino, G. and Manconi, A. and Clague, J. and Shan, W. and Chiarle, M.},
  title = {Engineering geology for society and territory - Volume 1: Climate change and engineering geology},
  journal = {Engineering Geology for Society and Territory - Volume 1: Climate Change and Engineering Geology},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {1-572},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945120831&doi=10.1007%2f978-3-319-09300-0&partnerID=40&md5=8c840f9d8bfdbc23de43b70dd3ad8945},
  doi = {10.1007/978-3-319-09300-0}
}
Lollino G, Manconi A, Giordan D, Allasia P and Baldo M (2015), "Infrastructure in geohazard contexts: The importance of automatic and near-real-time monitoring", Environmental Security of the European Cross-Border Energy Supply Infrastructure. , pp. 73-89. Springer Netherlands.
Abstract: The analysis and interpretation of ground deformation plays an important role in monitoring activities aimed at ensuring the safety of people and/or infrastructure in geohazard scenarios such as earthquakes, volcanic activity and landslides. Nowadays, a wide spectrum of instruments and methods is available, ranging from in-situ to remote sensing approaches. However, the research described here was primarily to develop automatic, and increasingly accurate, monitoring instruments, while acknowledging that the available tools for an efficient exploitation, understanding and interpretation of the measurements made still lack efficiency. In this work, three relevant geohazard case-studies are described where automatic and near-real-time systems allowed the monitoring of surface displacements and deep-seated deformation. The results demonstrate that the automatic and near-real-time acquisition of measurements is important but that this concept has to be extended also to the data processing and its communication. This is particularly important in critical geohazard scenarios, where monitoring activities are fundamental to support early warning systems. Springer Science+Business Media Dordrecht 2015.
BibTeX:
@book{Lollino201573,
  author = {Lollino, G. and Manconi, A. and Giordan, D. and Allasia, P. and Baldo, M.},
  title = {Infrastructure in geohazard contexts: The importance of automatic and near-real-time monitoring},
  journal = {Environmental Security of the European Cross-Border Energy Supply Infrastructure},
  publisher = {Springer Netherlands},
  year = {2015},
  pages = {73-89},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943232880&doi=10.1007%2f978-94-017-9538-8_6&partnerID=40&md5=7df04ba85ce052c8ea565d14fe54064d},
  doi = {10.1007/978-94-017-9538-8_6}
}
Lollino G, Manconi A, Guzzetti F, Culshaw M, Bobrowsky P and Luino F (2015), "Engineering geology for society and territory - volume 5: Urban geology, sustainable planning and landscape exploitation", Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation. , pp. 1-1400. Springer International Publishing.
Abstract: This book is one out of 8 IAEG XII Congress volumes, and deals with the theme of urban geology. Along with a rapidly growing world population, the wave of urban growth continues, causing cities to swell and new metropolitan centers to emerge. These global trends also open new ventures for underground city development. Engineering geology plays a major role in facing the increasing issues of the urban environment, such as: finding aggregates for construction works; providing adequate water supply and waste management; solving building problems associated to geological and geomorphological conditions; evaluating host rock conditions for underground constructions; preventing or mitigating geological and seismic hazards. Furthermore, this book illustrates recent advancements in sustainable land use planning, which includes conservation, protection, reclamation and landscape impact of open pit mining and alternative power generation.The Engineering Geology for Society and Territory volumes of the IAEG XII Congress held in Torino from September 15-19, 2014, analyze the dynamic role of engineering geology in our changing world and build on the four main themes of the congress: environment, processes, issues and approaches. The congress topics and subject areas of the 8 IAEG XII Congress volumes are:1. Climate Change and Engineering Geology2. Landslide Processes River Basins3. Reservoir Sedimentation and Water Resources4. Marine and Coastal Processes Urban Geology5. Sustainable Planning and Landscape Exploitation6. Applied Geology for Major Engineering Projects7. Education, Professional Ethics and Public Recognition of Engineering Geology8. Preservation of Cultural Heritage. Springer International Publishing Switzerland 2015.
BibTeX:
@book{Lollino20151b,
  author = {Lollino, G. and Manconi, A. and Guzzetti, F. and Culshaw, M. and Bobrowsky, P. and Luino, F.},
  title = {Engineering geology for society and territory - volume 5: Urban geology, sustainable planning and landscape exploitation},
  journal = {Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {1-1400},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944538564&doi=10.1007%2f978-3-319-09048-1&partnerID=40&md5=4ab26b9dc302b61494c2c63078924482},
  doi = {10.1007/978-3-319-09048-1}
}
Magnard C, Small D and Meier E (2015), "Phase noise investigation of maximum likelihood estimation method for airborne multibaseline SAR interferometry", In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives. Vol. 40,3W2, pp. 121-125. International Society for Photogrammetry and Remote Sensing.
Abstract: The phase estimation of cross-track multibaseline synthetic aperture interferometric data is usually thought to be very efficiently achieved using the maximum likelihood (ML) method. The suitability of this method is investigated here as applied to airborne single pass multibaseline data. Experimental interferometric data acquired with a Ka-band sensor were processed using (a) a ML method that fuses the complex data from all receivers and (b) a coarse-to-fine method that only uses the intermediate baselines to unwrap the phase values from the longest baseline. The phase noise was analyzed for both methods: in most cases, a small improvement was found when the ML method was used.
BibTeX:
@conference{Magnard2015121,
  author = {Magnard, C. and Small, D. and Meier, E.},
  editor = {Heipke C., Stilla U.},
  title = {Phase noise investigation of maximum likelihood estimation method for airborne multibaseline SAR interferometry},
  booktitle = {International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives},
  publisher = {International Society for Photogrammetry and Remote Sensing},
  year = {2015},
  volume = {40,3W2},
  pages = {121-125},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925366150&doi=10.5194%2fisprsarchives-XL-3-W2-121-2015&partnerID=40&md5=20e04aa4ddad1ab986141b5e72b9fbce},
  doi = {10.5194/isprsarchives-XL-3-W2-121-2015}
}
Malnes E, Buanes A, Nagler T, Bippus G, Gustafsson D, Schiller C, Metsamaki S, Pulliainen J, Luojus K, Larsen H, Solberg R, Diamandi A and Wiesmann A (2015), "User requirements for the snow and land ice services - CryoLand", Cryosphere. Vol. 9(3), pp. 1191-1202. Copernicus GmbH.
Abstract: CryoLand (2011-2015) is a project carried out within the 7th Framework of the European Commission aimed at developing downstream services for monitoring seasonal snow, glaciers and lake/river ice primarily based on satellite remote sensing. The services target private and public users from a wide variety of application areas, and aim to develop sustainable services after the project is completed. The project has performed a thorough user requirement survey in order to derive targeted requirements for the service and provide recommendations for the design and priorities of the service. In this paper we describe the methods used, the major findings in this user survey, and how we used the results to design and specify the CryoLand snow and land ice service. The user requirement analysis shows that a European operational snow and land ice service is required and that there exists developed cryosphere products that can meet the specific needs. The majority of the users were mainly interested not only in the snow services, but also the lake/river ice products and the glacier products were desired. Author(s) 2015.
BibTeX:
@article{Malnes20151191,
  author = {Malnes, E. and Buanes, A. and Nagler, T. and Bippus, G. and Gustafsson, D. and Schiller, C. and Metsamaki, S. and Pulliainen, J. and Luojus, K. and Larsen, H.E. and Solberg, R. and Diamandi, A. and Wiesmann, A.},
  title = {User requirements for the snow and land ice services - CryoLand},
  journal = {Cryosphere},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {9},
  number = {3},
  pages = {1191-1202},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930935219&doi=10.5194%2ftc-9-1191-2015&partnerID=40&md5=767ceae2ae17c93d6315ecb7a059eaa3},
  doi = {10.5194/tc-9-1191-2015}
}
Manconi A and Giordan D (2015), "Landslide early warning based on failure forecast models: The example of the Mt. de la Saxe rockslide, northern Italy", Natural Hazards and Earth System Sciences. Vol. 15(7), pp. 1639-1644. Copernicus GmbH.
Abstract: We apply failure forecast models by exploiting near-real-time monitoring data for the La Saxe rockslide, a large unstable slope threatening Aosta Valley in northern Italy. Starting from the inverse velocity theory, we analyze landslide surface displacements automatically and in near real time on different temporal windows and apply straightforward statistical methods to obtain confidence intervals on the estimated time of failure. Here, we present the result obtained for the La Saxe rockslide, a large unstable slope located in Aosta Valley, northern Italy. Based on this case study, we identify operational thresholds that are established on the reliability of the forecast models. Our approach is aimed at supporting the management of early warning systems in the most critical phases of the landslide emergency. Author(s) 2015.
BibTeX:
@article{Manconi20151639,
  author = {Manconi, A. and Giordan, D.},
  title = {Landslide early warning based on failure forecast models: The example of the Mt. de la Saxe rockslide, northern Italy},
  journal = {Natural Hazards and Earth System Sciences},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {15},
  number = {7},
  pages = {1639-1644},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938405264&doi=10.5194%2fnhess-15-1639-2015&partnerID=40&md5=03c4bd3d3082b2a2da21276f71e5c9cc},
  doi = {10.5194/nhess-15-1639-2015}
}
Margottini C, Antidze N, Corominas J, Crosta G, Frattini P, Gigli G, Giordan D, Iwasaky I, Lollino G, Manconi A, Marinos P, Scavia C, Sonnessa A, Spizzichino D and Vacheishvili N (2015), "Landslide hazard, monitoring and conservation strategy for the safeguard of Vardzia Byzantine monastery complex, Georgia", Landslides. Vol. 12(1), pp. 193-204. Springer Verlag.
Abstract: This paper reports preliminary results of a feasibility project developed in cooperation with National Agency for Cultural Heritage Preservation of Georgia, and aimed at envisaging the stability conditions of the Vardzia monastery slope (rupestrian city cave in the south-western Georgia). The aim is the implementation of a low-impact monitoring system together with long-term mitigation/conservation policies. A field analysis was conducted to reconstruct geometry of the rocky cliff, characteristics of discontinuities, main failure modes, and volume of potential unstable blocks and geomechanical parameters. Instability processes are the combination of causative factors such as the following: lithology, frequency and orientation of discontinuities, slope orientation, physical and mechanical characteristics of slope-forming materials, and morphological and hydrological boundary conditions. The combined adoption of different survey techniques (e.g., 3D laser scanner, ground-based radar interferometry) could be the best solution in the interdisciplinary field of cultural heritage preservation policies. The collected data will be the basis for future activities to be completed in collaboration with local authorities for a complete hazard and risk characterization for the monastery site and the development of an early warning system to allow safe exploitation for touristic activities and for historical site preservation. 2015, Springer-Verlag Berlin Heidelberg.
BibTeX:
@article{Margottini2015193,
  author = {Margottini, C. and Antidze, N. and Corominas, J. and Crosta, G.B. and Frattini, P. and Gigli, G. and Giordan, D. and Iwasaky, I. and Lollino, G. and Manconi, A. and Marinos, P. and Scavia, C. and Sonnessa, A. and Spizzichino, D. and Vacheishvili, N.},
  title = {Landslide hazard, monitoring and conservation strategy for the safeguard of Vardzia Byzantine monastery complex, Georgia},
  journal = {Landslides},
  publisher = {Springer Verlag},
  year = {2015},
  volume = {12},
  number = {1},
  pages = {193-204},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922447948&doi=10.1007%2fs10346-014-0548-z&partnerID=40&md5=80a419a428d513ab17bea7c3ad5385a6},
  doi = {10.1007/s10346-014-0548-z}
}
Metsamaki S, Pulliainen J, Salminen M, Luojus K, Wiesmann A, Solberg R, Bottcher K, Hiltunen M and Ripper E (2015), "Introduction to GlobSnow Snow Extent products with considerations for accuracy assessment", Remote Sensing of Environment. Vol. 156, pp. 96-108. Elsevier Inc..
Abstract: The European Space Agency's Data User Element (DUE) project GlobSnow was established to create a global database of Snow Extent and Snow Water Equivalent. The Snow Extent (SE) product portfolio provided within ESA DUE GlobSnow (2008-2014) is introduced and described, with a special focus on the Daily Fractional Snow Cover (DFSC) of the SE version 2.0 and its successor 2.1 released in 2013-2014. The fractional snow retrieval uses the SCAmod method designed ecpecially to enable accurate snow mapping including forests. The basics of the methodology are presented, as well as the cloud screening method applied in SE production. Considerations for future validations together with discussion on some current issues and potential inaccuracies are presented. One focus of the investigation is on the representativeness of reference FSC generated from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM. +) data, with a particular interest in forested areas. Two methods for reference data generation are investigated. When comparing the GlobSnow Daily Fractional Snow Cover to these reference data, we try to identify how the comparison reflects the possible inaccuracies of the DFSC and to define the conditions where the reference data are not representative. It is obvious that the evaluation result strongly depends on the quality of the reference data, and that the two methods investigated cannot provide representative reference data for dense forests. For fully snow-covered dense conifer forest area in Finland, a Root Mean Squared Error of 20-30% was obtained from comparisons although DFSC indicated full snow cover correctly. These first evaluations would indicate a good performance of GlobSnow SE products in forests; however, this does not necessarily show up in validations due to the non-representativeness of the reference data. It is also concluded that GlobSnow SE products are sensitive to the representativeness of the applied SCAmod parameters and that FSC overestimations may occur in dense forests. GlobSnow SE products are available at www.globsnow.info/se/. 2014 Elsevier Inc.
BibTeX:
@article{Metsamaki201596,
  author = {Metsamaki, S. and Pulliainen, J. and Salminen, M. and Luojus, K. and Wiesmann, A. and Solberg, R. and Bottcher, K. and Hiltunen, M. and Ripper, E.},
  title = {Introduction to GlobSnow Snow Extent products with considerations for accuracy assessment},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {156},
  pages = {96-108},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907999764&doi=10.1016%2fj.rse.2014.09.018&partnerID=40&md5=c989574e145c0babc35d984cb9ad0a4f},
  doi = {10.1016/j.rse.2014.09.018}
}
Paul F, Bolch T, Kaab A, Nagler T, Nuth C, Scharrer K, Shepherd A, Strozzi T, Ticconi F, Bhambri R, Berthier E, Bevan S, Gourmelen N, Heid T, Jeong S, Kunz M, Lauknes T, Luckman A, Merryman Boncori J, Moholdt G, Muir A, Neelmeijer J, Rankl M, VanLooy J and Van Niel T (2015), "The glaciers climate change initiative: Methods for creating glacier area, elevation change and velocity products", Remote Sensing of Environment. Vol. 162, pp. 408-426. Elsevier Inc..
Abstract: Glaciers and their changes through time are increasingly obtained from a wide range of satellite sensors. Due to the often remote location of glaciers in inaccessible and high-mountain terrain, satellite observations frequently provide the only available measurements. Furthermore, satellite data provide observations of glacier characteristics that are difficult to monitor using ground-based measurements, thus complementing the latter. In the Glaciers_cci project of the European Space Agency (ESA), three of these characteristics are investigated in detail: glacier area, elevation change and surface velocity. We use (a) data from optical sensors to derive glacier outlines, (b) digital elevation models from at least two points in time, (c) repeat altimetry for determining elevation changes, and (d) data from repeat optical and microwave sensors for calculating surface velocity. For the latter, the two sensor types provide complementary information in terms of spatio-temporal coverage. While (c) and (d) can be generated mostly automatically, (a) and (b) require the intervention of an analyst. Largely based on the results of various round robin experiments (multi-analyst benchmark studies) for each of the products, we suggest and describe the most suitable algorithms for product creation and provide recommendations concerning their practical implementation and the required post-processing. For some of the products (area, velocity) post-processing can influence product quality more than the main-processing algorithm. 2013 Elsevier Inc.
BibTeX:
@article{Paul2015408,
  author = {Paul, F. and Bolch, T. and Kaab, A. and Nagler, T. and Nuth, C. and Scharrer, K. and Shepherd, A. and Strozzi, T. and Ticconi, F. and Bhambri, R. and Berthier, E. and Bevan, S. and Gourmelen, N. and Heid, T. and Jeong, S. and Kunz, M. and Lauknes, T.R. and Luckman, A. and Merryman Boncori, J.P. and Moholdt, G. and Muir, A. and Neelmeijer, J. and Rankl, M. and VanLooy, J. and Van Niel, T.},
  title = {The glaciers climate change initiative: Methods for creating glacier area, elevation change and velocity products},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {162},
  pages = {408-426},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928489795&doi=10.1016%2fj.rse.2013.07.043&partnerID=40&md5=1fade622fe9648d57268e614b18346bd},
  doi = {10.1016/j.rse.2013.07.043}
}
Proksch M, Matzler C, Wiesmann A, Lemmetyinen J, Schwank M, Lowe H and Schneebeli M (2015), "MEMLS3&a: Microwave Emission Model of Layered Snowpacks adapted to include backscattering", Geoscientific Model Development. Vol. 8(8), pp. 2611-2626. Copernicus GmbH.
Abstract: The Microwave Emission Model of Layered Snowpacks (MEMLS) was originally developed for microwave emissions of snowpacks in the frequency range 5-100 GHz. It is based on six-flux theory to describe radiative transfer in snow including absorption, multiple volume scattering, radiation trapping due to internal reflection and a combination of coherent and incoherent superposition of reflections between horizontal layer interfaces. Here we introduce MEMLS3&a, an extension of MEMLS, which includes a backscatter model for active microwave remote sensing of snow. The reflectivity is decomposed into diffuse and specular components. Slight undulations of the snow surface are taken into account. The treatment of like- and cross-polarization is accomplished by an empirical splitting parameter q. MEMLS3&a (as well as MEMLS) is set up in a way that snow input parameters can be derived by objective measurement methods which avoid fitting procedures of the scattering efficiency of snow, required by several other models. For the validation of the model we have used a combination of active and passive measurements from the NoSREx (Nordic Snow Radar Experiment) campaign in Sodankyla, Finland. We find a reasonable agreement between the measurements and simulations, subject to uncertainties in hitherto unmeasured input parameters of the backscatter model. The model is written in Matlab and the code is publicly available for download through the following website: http://www.iapmw.unibe.ch/research/projects/snowtools/memls.html. Author(s) 2015.
BibTeX:
@article{Proksch20152611,
  author = {Proksch, M. and Matzler, C. and Wiesmann, A. and Lemmetyinen, J. and Schwank, M. and Lowe, H. and Schneebeli, M.},
  title = {MEMLS3&a: Microwave Emission Model of Layered Snowpacks adapted to include backscattering},
  journal = {Geoscientific Model Development},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {8},
  number = {8},
  pages = {2611-2626},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940176762&doi=10.5194%2fgmd-8-2611-2015&partnerID=40&md5=d76e2277776becab5539aa3cb9ceadf4},
  doi = {10.5194/gmd-8-2611-2015}
}
Robson B, Nuth C, Dahl S, Holbling D, Strozzi T and Nielsen P (2015), "Automated classification of debris-covered glaciers combining optical, SAR and topographic data in an object-based environment", Remote Sensing of Environment. Vol. 170, pp. 372-387. Elsevier Inc..
Abstract: Satellite imagery is increasingly used to monitor glacier area changes and create glacier inventories. Robust and efficient pixel-based band ratios have proven to be accurate for automatically delineating clean glacier ice, however such classifications are restricted on debris-covered ice due to its spectral similarity with surrounding terrain. Object-Based Image Analysis (OBIA) has emerged as a new analysis technique within remote sensing. It offers many advantages over pixel-based classification techniques due to the ability to work with multiple data sources and handle data contextually and hierarchically. By making use of OBIA capabilities we automatically classify clean ice and debris-covered ice in the challenging area surrounding Mount Manaslu in Nepal using optical (Landsat 8), topographic (void-filled SRTM) and SAR coherence (ALOS PALSAR) data. Clean ice was classified with a mean accuracy of 93% whilst debris-covered ice was classified with an accuracy of 83% when compared to manually corrected outlines, providing a total glacier accuracy of 91%. With further developments in the classification, steep tributary sections of ice could be contextually included, raising the accuracy to over 94%. One prominent advantage of OBIA is that it allows some post-processing and correction of the glacier outlines automatically, reducing the amount of manual correction needed. OBIA incorporating SAR coherence data is recommended for future mapping of debris-covered ice. 2015 Elsevier Inc.
BibTeX:
@article{Robson2015372,
  author = {Robson, B.A. and Nuth, C. and Dahl, S.O. and Holbling, D. and Strozzi, T. and Nielsen, P.R.},
  title = {Automated classification of debris-covered glaciers combining optical, SAR and topographic data in an object-based environment},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {170},
  pages = {372-387},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944065736&doi=10.1016%2fj.rse.2015.10.001&partnerID=40&md5=018606e86785d4a4c1bb4a4707c94990},
  doi = {10.1016/j.rse.2015.10.001}
}
Santoro M, Beaudoin A, Beer C, Cartus O, Fransson J, Hall R, Pathe C, Schmullius C, Schepaschenko D, Shvidenko A, Thurner M and Wegmüller U (2015), "Forest growing stock volume of the northern hemisphere: Spatially explicit estimates for 2010 derived from Envisat ASAR", Remote Sensing of Environment. Vol. 168, pp. 316-334. Elsevier Inc..
Abstract: This paper presents and assesses spatially explicit estimates of forest growing stock volume (GSV) of the northern hemisphere (north of 10°N) from hyper-temporal observations of Envisat Advanced Synthetic Aperture Radar (ASAR) backscattered intensity using the BIOMASAR algorithm. Approximately 70,000 ASAR images at a pixel size of 0.01° were used to estimate GSV representative for the year 2010. The spatial distribution of the GSV across four ecological zones (polar, boreal, temperate, subtropical) was well captured by the ASAR-based estimates. The uncertainty of the retrieved GSV was smallest in boreal and temperate forest (<30% for approximately 80% of the forest area) and largest in subtropical forest. ASAR-derived GSV averages at the level of administrative units were mostly in agreement with inventory-derived estimates. Underestimation occurred in regions of very high GSV (>300m3/ha) and fragmented forest landscapes. For the major forested countries within the study region, the relative RMSE between ASAR-derived GSV averages at provincial level and corresponding values from National Forest Inventory was between 12% and 45% (average: 29%). 2015 Elsevier Inc.
BibTeX:
@article{Santoro2015316,
  author = {Santoro, M. and Beaudoin, A. and Beer, C. and Cartus, O. and Fransson, J.E.S. and Hall, R.J. and Pathe, C. and Schmullius, C. and Schepaschenko, D. and Shvidenko, A. and Thurner, M. and Wegmüller, U.},
  title = {Forest growing stock volume of the northern hemisphere: Spatially explicit estimates for 2010 derived from Envisat ASAR},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {168},
  pages = {316-334},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938319734&doi=10.1016%2fj.rse.2015.07.005&partnerID=40&md5=859d12cca27db2263d40ce493fc6ca54},
  doi = {10.1016/j.rse.2015.07.005}
}
Santoro M, Eriksson L and Fransson J (2015), "Reviewing ALOS PALSAR backscatter observations for stem volume retrieval in Swedish forest", Remote Sensing. Vol. 7(4), pp. 4290-4317. MDPI AG.
Abstract: Between 2006 and 2011, the Advanced Land Observing Satellite (ALOS) Phased Array L-type Synthetic Aperture Radar (PALSAR) instrument acquired multi-temporal datasets under several environmental conditions and multiple configurations of look angle and polarization. The extensive archive of SAR backscatter observations over the forest test sites of Krycklan (boreal) and Remningstorp (hemi-boreal), Sweden, was used to assess the retrieval of stem volume at stand level. The retrieval was based on the inversion of a simple Water Cloud Model with gaps; single estimates of stem volume are then combined to obtain the final multi-temporal estimate. The model matched the relationship between the SAR backscatter and the stem volume under all configurations. The retrieval relative Root Mean Square Error (RMSE) differed depending upon environmental conditions, polarization and look angle. Stem volume was best retrieved in Krycklan using only HV-polarized data acquired under unfrozen conditions with a look angle of 34.3° (relative RMSE: 44.0%). In Remningstorp, the smallest error was obtained using only HH-polarized data acquired under predominantly frozen conditions with a look angle of 34.3° (relative RMSE: 35.1%). The relative RMSE was below 30% for stands >20 ha, suggesting high accuracy of ALOS PALSAR estimates of stem volumes aggregated at moderate resolution. 2015 by the authors; licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Santoro20154290,
  author = {Santoro, M. and Eriksson, L.E.B. and Fransson, J.E.S.},
  title = {Reviewing ALOS PALSAR backscatter observations for stem volume retrieval in Swedish forest},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2015},
  volume = {7},
  number = {4},
  pages = {4290-4317},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937932908&doi=10.3390%2frs70404290&partnerID=40&md5=3f699bcdeb1352ff2e473ca97476828c},
  doi = {10.3390/rs70404290}
}
Santoro M, Wegmüller U, Lamarche C, Bontemps S, Defourny P and Arino O (2015), "Strengths and weaknesses of multi-year Envisat ASAR backscatter measurements to map permanent open water bodies at global scale", Remote Sensing of Environment. Vol. 171, pp. 185-201. Elsevier Inc..
Abstract: The mapping of water bodies at global scale has been undertaken primarily using multi-spectral optical Earth Observation data. Limitations of optical data associatedwith non-uniform and temporally variable spectral signatures suggested investigating alternative approaches towards a more consistent and reliable detection of water bodies. Multi-year (2005-2012) observations of SAR backscattered intensities at moderate resolution from the Envisat Advanced Synthetic Aperture Radar (ASAR) instrument were used in this study to generate an indicator of open permanent water bodies (SAR-WBI) for the year 2010 time frame and for all land surfaces excluding Antarctica and the Greenland ice sheet. A first map of potential water bodies with a spatial resolution of 150 m was obtained with a global detection algorithm based on a set of thresholds applied to multi-temporal metrics of the SAR backscatter (temporal variability, TV, and minimum backscatter, MB). Local refinements were then used to reduce systematic commission and omission errors (4.6% of the total area mapped) due to the similarity of TV and MB over open water bodies and other land surface types primarily in cold and arid environments. The refinement rules are here explained by means of a detailed signature analysis of the SAR backscatter in such environments. The accuracy of the SAR-WBIwas 80%when compared against 2078 manually interpreted footprints with a size of 150 × 150 m2. Omission errors were primarily observed along coast- and shorelines whereas commission errors were associated with (i) ephemeral water bodies, (ii) seasonally inundated areas, and (iii) an incorrect choice of the local refinement. 2015 Elsevier Inc.
BibTeX:
@article{Santoro2015185,
  author = {Santoro, M. and Wegmüller, U. and Lamarche, C. and Bontemps, S. and Defourny, P. and Arino, O.},
  title = {Strengths and weaknesses of multi-year Envisat ASAR backscatter measurements to map permanent open water bodies at global scale},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2015},
  volume = {171},
  pages = {185-201},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946542137&doi=10.1016%2fj.rse.2015.10.031&partnerID=40&md5=44f6814afd98dec0c446ca3bcae50ae3},
  doi = {10.1016/j.rse.2015.10.031}
}
Santoro M, Wegmüller U, Wiesmann A, Lamarche C, Bontemps S, Defourny P and Arino O (2015), "Assessing Envisat ASAR and Sentinel-1 multi-temporal observations to map open water bodies", In Proceedings of the 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2015. , pp. 614-619. Institute of Electrical and Electronics Engineers Inc..
Abstract: C-band observations of the SAR backscatter from the Envisat ASAR (2005-2012) and Sentinel-1 (2014-ongoing) instruments are reviewed to understand their suitability to detect of open water bodies. The temporal variability (TV) and the minimum backscatter (MB) of ASAR backscatter were fed to a simple algorithm based on thresholds to obtain an indicator of water bodies globally with a spatial resolution of 150 m. Confusion occurred either in the case of irregular acquisitions of ASAR images or in cold and arid regions where the multi-temporal metrics based on the multi-year ASAR dataset were often similar to values obtained over open water bodies. With Sentinel-1, there are clear chances to improve the mapping of water bodies considering the dual-polarization capability, the higher spatial resolution and the more consistent observation strategy. First examples from a test site in Sweden show that average and minimum cross-polarized backscatter are suited for water body mapping. 2015 IEEE.
BibTeX:
@conference{Santoro2015614,
  author = {Santoro, M. and Wegmüller, U. and Wiesmann, A. and Lamarche, C. and Bontemps, S. and Defourny, P. and Arino, O.},
  title = {Assessing Envisat ASAR and Sentinel-1 multi-temporal observations to map open water bodies},
  booktitle = {Proceedings of the 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2015},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  pages = {614-619},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957613901&doi=10.1109%2fAPSAR.2015.7306283&partnerID=40&md5=a44efb3e0f8779a43a182929f310ad01},
  doi = {10.1109/APSAR.2015.7306283}
}
Schmullius C, Thiel C, Pathe C and Santoro M (2015), "Radar time series for land cover and forest mapping", Remote Sensing and Digital Image Processing. Vol. 22, pp. 323-356. Springer International Publishing.
Abstract: Radar time series are powerful means to improve retrieval algorithms about land surface characteristics in the following ways: (i) as information for identification of land surface conditions, (ii) as source of multivariate statistics for mapping methodologies, (iii) to select the right scene(s) for dedicated retrieval procedures, or (iv) to train model parameters in physical retrievals. Albeit radar data from air- and spaceborne platforms have been investigated since 40 years, operational applications are limited - partly due to the non-intuitive handling of complex microwave backscatter signals, and partly due to restricted geometric and temporal resolutions or frequency and polarization constraints. This chapter gives an overview of 20 years of pilot projects performed by the authors and their collaborators with the goal of large-area radar data exploration. All studies lead to innovative pre-operational applications, several with promising discoveries that can now be realized with a new and expanding fleet of radar satellites. Four case studies for land cover, forest mapping, forest cover change and savannah monitoring conclude this chapter. Springer International Publishing Switzerland 2015.
BibTeX:
@article{Schmullius2015323,
  author = {Schmullius, C. and Thiel, C. and Pathe, C. and Santoro, M.},
  title = {Radar time series for land cover and forest mapping},
  journal = {Remote Sensing and Digital Image Processing},
  publisher = {Springer International Publishing},
  year = {2015},
  volume = {22},
  pages = {323-356},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84980010210&doi=10.1007%2f978-3-319-15967-6_16&partnerID=40&md5=4c92d89b74813b5378544b2d41c2d571},
  doi = {10.1007/978-3-319-15967-6_16}
}
Schwank M, Matzler C, Wiesmann A, Wegmüller U, Pulliainen J, Lemmetyinen J, Rautiainen K, Derksen C, Toose P and Drusch M (2015), "Snow Density and Ground Permittivity Retrieved from L-Band Radiometry: A Synthetic Analysis", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 8(8), pp. 3833-3845. Institute of Electrical and Electronics Engineers.
Abstract: A synthetic study was performed to determine the potential to retrieve dry-snow density and ground permittivity from multiangular L-band brightness temperatures. The thereto employed emission model was developed from parts of the 'microwave emission model of layered snowpacks' (MEMLS) coupled with components adopted from the 'L-band microwave emission of the biosphere' (L-MEB) model. The restriction to L-band made it possible to avoid scattering and absorption in the snow volume, leading to a rather simple formulation of our emission model. Parametric model studies revealed L-band signatures related to the mass density of the bottom layer of a dry snowpack. This gave rise to the presented analysis of corresponding retrieval performances based on measurements synthesized with the developed emission model. The question regarding the extent to which random noise translates into retrieval uncertainties was investigated. It was found that several classes of snow densities could be distinguished by retrievals based on L-band brightness temperatures with soil moisture and ocean salinity (SMOS)-typical data quality. Further synthetic retrievals demonstrated that propagation effects must be taken into account in dry snow even at L-band when retrieving permittivity of the underlying ground surface. Accordingly, current SMOS-based retrievals seam to underestimate actual ground permittivity by typically 30% as dry snow is wrongly considered as 'invisible.' Although experimental validation has not yet been performed, the proposed retrieval approach is seen as a promising step toward the full exploitation of L-band brightness temperatures available from current and future satellite Earth observation missions, especially over the cold regions of the Northern Hemisphere. 2008-2012 IEEE.
BibTeX:
@article{Schwank20153833,
  author = {Schwank, M. and Matzler, C. and Wiesmann, A. and Wegmüller, U. and Pulliainen, J. and Lemmetyinen, J. and Rautiainen, K. and Derksen, C. and Toose, P. and Drusch, M.},
  title = {Snow Density and Ground Permittivity Retrieved from L-Band Radiometry: A Synthetic Analysis},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2015},
  volume = {8},
  number = {8},
  pages = {3833-3845},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961945090&doi=10.1109%2fJSTARS.2015.2422998&partnerID=40&md5=6aa21a8daaaead83a5b4f0936b672ffc},
  doi = {10.1109/JSTARS.2015.2422998}
}
Siddique M, Hajnsek I, Wegmüller U and Frey O (2015), "Investigating the combined use of differential SAR tomography and PSI for spatio-temporal inversion", In 2015 Joint Urban Remote Sensing Event, JURSE 2015. Institute of Electrical and Electronics Engineers Inc..
Abstract: Persistent Scatterer Interferometry (PSI) inherently assumes a single temporally coherent scatterer inside a range-azimuth resolution cell. This restriction leads to the rejection of numerous persistent scatterer (PS) candidates, particularly in urban areas where layovers occur frequently. Moreover, in case of high-rise buildings, it is necessary to compensate the phase associated with thermal expansion in an iterative way. It is worthwhile to approach tomographic techniques to address these concerns. SAR tomography has the potential to separate scatterers in elevation, thus resolving layover. Differential SAR tomography additionally allows retrieval of deformation parameters, including a possible thermal expansion term. In this paper, we investigate the combined use of SAR tomographic approaches and PSI for elevation and deformation estimation. Results are presented for an interferometric time-series of 50 TerraSAR-X stripmap images acquired over Barcelona city. Spatio-temporal inversion of scatterers along the façade of a high-rise building is presented as a special case. 2015 IEEE.
BibTeX:
@conference{Siddique2015b,
  author = {Siddique, M.A. and Hajnsek, I. and Wegmüller, U. and Frey, O.},
  title = {Investigating the combined use of differential SAR tomography and PSI for spatio-temporal inversion},
  booktitle = {2015 Joint Urban Remote Sensing Event, JURSE 2015},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938894010&doi=10.1109%2fJURSE.2015.7120504&partnerID=40&md5=c5ebbe8d0efad3d89f46ce27858f397f},
  doi = {10.1109/JURSE.2015.7120504}
}
Siddique M, Hajnsek I, Wegmüller U and Frey O (2015), "Towards the integration of SAR tomography and PSI for improved deformation assessment in urban areas", In European Space Agency, (Special Publication) ESA SP. Vol. SP-731 European Space Agency.
Abstract: Persistent scatterer interferometry (PSI) typically rejects the range-azimuth pixels containing multiple scatterers, such as in a layover scenario. Since layovers occur frequently in urban areas, a significant number of candidates may get rejected. SAR tomography allows for resolving layover and has thus the potential to extend the spatial sampling of deformation measurements to layoveraffected areas. Using extended phase models, also taking into account temperature, an improved simultaneous estimation of elevation, deformation velocity, and temperature-induced scatterer displacement is possible. This paper explores the combined use of PSI and SAR tomography for deformation analysis in urban areas, using a multibaseline and multitemporal interferometric stack of stripmap TerraSAR-X images acquired over the city of Barcelona.
BibTeX:
@conference{Siddique2015a,
  author = {Siddique, M.A. and Hajnsek, I. and Wegmüller, U. and Frey, O.},
  editor = {Ouwehand L.},
  title = {Towards the integration of SAR tomography and PSI for improved deformation assessment in urban areas},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2015},
  volume = {SP-731},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961797224&partnerID=40&md5=bcf3d1064a504ae2ea3c987471325878}
}
Siddique M, Wegmüller U, Hajnsek I and Frey O (2015), "SAR tomography for spatio-temporal inversion of point-like scatterers in urban areas", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. Vol. 2015-November, pp. 5272-5275. Institute of Electrical and Electronics Engineers Inc..
Abstract: Persistent scatterer interferometry (PSI) assumes the presence of a single temporally coherent scatterer in a range-azimuth pixel. Multiple scatterers interfering in the same pixel, as for the case of a layover, are typically rejected. Conventional SAR tomography (3D SAR) is a means to separate the individual scatterers in layover. Advanced tomographic inversion approaches employing extended phase models additionally allow simultaneous retrieval of scatterer elevation and deformation parameters. In this way, SAR tomography can increase deformation sampling and thereby complement a PSI-based analysis. This paper investigates the use of tomography as an add-on to PSI for spatio-temporal inversion of single and double scatterers in urban areas. Results are provided on an interferometric stack of 50 stripmap TerraSAR-X images acquired over the city of Barcelona. 2015 IEEE.
BibTeX:
@conference{Siddique20155272,
  author = {Siddique, M.A. and Wegmüller, U. and Hajnsek, I. and Frey, O.},
  title = {SAR tomography for spatio-temporal inversion of point-like scatterers in urban areas},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  volume = {2015-November},
  pages = {5272-5275},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962505282&doi=10.1109%2fIGARSS.2015.7327024&partnerID=40&md5=e2dfbc7b75d848679e775726b40fd94e},
  doi = {10.1109/IGARSS.2015.7327024}
}
Strozzi T, Raetzo H, Wegmüller U, Papke J, Caduff R, Werner C and Wiesmann A (2015), "Satellite and Terrestrial Radar Interferometry for the Measurement of Slope Deformation", Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation. , pp. 161-165. Springer International Publishing.
Abstract: Synergistic use of satellite and terrestrial radar interferometry was considered for the measurement of slope deformation in the Mattervalley (Canton of Valais, Switzerland). Highest rates of movement of more than 1cm/day were measured only with terrestrial radar interferometry, because of the large time interval between satellite SAR observations. Summer TerraSAR-X and Cosmo-SkyMed interferograms as well as terrestrial radar interferometry campaigns repeated with a time interval of a few days were jointly considered for the study of landslides moving at rates of dm/year. Persistent scatterer interferometric analyses conducted with ERS-1/2, ENVISAT, Radarsat-2, TerraSAR-X and Cosmo-Sky Med images were finally used to detect the slowest moving landslides, with rates of movement below a few cm/yr in the line-of-sight direction. . Springer International Publishing Switzerland 2015.
BibTeX:
@book{Strozzi2015161,
  author = {Strozzi, T. and Raetzo, H. and Wegmüller, U. and Papke, J. and Caduff, R. and Werner, C. and Wiesmann, A.},
  title = {Satellite and Terrestrial Radar Interferometry for the Measurement of Slope Deformation},
  journal = {Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {161-165},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944573073&doi=10.1007%2f978-3-319-09048-1_32&partnerID=40&md5=7f3386ea00538d8b8107596f02df3c98},
  doi = {10.1007/978-3-319-09048-1_32}
}
Tanase M, Ismail I, Lowell K, Karyanto O and Santoro M (2015), "Detecting and quantifying forest change: The potential of existing C- and X-band radar datasets", PLoS ONE. Vol. 10(6) Public Library of Science.
Abstract: This paper evaluates the opportunity provided by global interferometric radar datasets for monitoring deforestation, degradation and forest regrowth in tropical and semi-arid environments. The paper describes an easy to implement method for detecting forest spatial changes and estimating their magnitude. The datasets were acquired within space-borne high spatial resolutions radar missions at near-global scales thus being significant for monitoring systems developed under the United Framework Convention on Climate Change (UNFCCC). The approach presented in this paper was tested in two areas located in Indonesia and Australia. Forest change estimation was based on differences between a reference dataset acquired in February 2000 by the Shuttle Radar Topography Mission (SRTM) and TanDEM-X mission (TDM) datasets acquired in 2011 and 2013. The synergy between SRTM and TDM datasets allowed not only identifying changes in forest extent but also estimating their magnitude with respect to the reference through variations in forest height. 2015 Tanase et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
BibTeX:
@article{Tanase2015,
  author = {Tanase, M.A. and Ismail, I. and Lowell, K. and Karyanto, O. and Santoro, M.},
  title = {Detecting and quantifying forest change: The potential of existing C- and X-band radar datasets},
  journal = {PLoS ONE},
  publisher = {Public Library of Science},
  year = {2015},
  volume = {10},
  number = {6},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938508124&doi=10.1371%2fjournal.pone.0131079&partnerID=40&md5=68848cfa0bbe740691390daa1b483da9},
  doi = {10.1371/journal.pone.0131079}
}
Torrero L, Seoli L, Molino A, Giordan D, Manconi A, Allasia P and Baldo M (2015), "The use of micro-uav to monitor active landslide scenarios", Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation. , pp. 701-704. Springer International Publishing.
Abstract: We present a procedure to use micro-UAV (Unmanned Aerial Vehicles) to perform photogrammetry survey and monitoring analysis in landslide scenarios. The employed methodology is mainly composed of two phases: the first one is the UAV mission planning and execution, while the latter is the picture elaboration and alignment. The UAV used during all tests here described has been developed for photographic applications. Thanks to its –V— shape, propellers do not fall within camera field during normal flight operation and the eight motors configuration ensures more reliability in urban areas uses than a classical quadcopter configuration. The processing of the acquired photos relies on both standard photogrammetry procedure as well as innovative methods for photo alignment derived from computer vision algorithms. Examples of application are also provided to show the results and the potential of this methodology in real landslide scenarios. Springer International Publishing Switzerland 2015.
BibTeX:
@book{Torrero2015701,
  author = {Torrero, L. and Seoli, L. and Molino, A. and Giordan, D. and Manconi, A. and Allasia, P. and Baldo, M.},
  title = {The use of micro-uav to monitor active landslide scenarios},
  journal = {Engineering Geology for Society and Territory - Volume 5: Urban Geology, Sustainable Planning and Landscape Exploitation},
  publisher = {Springer International Publishing},
  year = {2015},
  pages = {701-704},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921923667&doi=10.1007%2f978-3-319-09048-1_136&partnerID=40&md5=c17587c5e1a0064efb76f5b1c5f03ef8},
  doi = {10.1007/978-3-319-09048-1_136}
}
Tosi L, Strozzi T, Da Lio C and Teatini P (2015), "Regional and local land subsidence at the Venice coastland by TerraSAR-X PSI", In Proceedings of the International Association of Hydrological Sciences. Vol. 372, pp. 199-205. Copernicus GmbH.
Abstract: Land subsidence occurred at the Venice coastland over the 2008-2011 period has been investigated by Persistent Scatterer Interferometry (PSI) using a stack of 90 TerraSAR-X stripmap images with a 3 m resolution and a 11-day revisiting time. The regular X-band SAR acquisitions over more than three years coupled with the very-high image resolution has significantly improved the monitoring of ground displacements at regional and local scales, e.g., the entire lagoon, especially the historical palaces, the MoSE large structures under construction at the lagoon inlets to disconnect the lagoon from the Adriatic Sea during high tides, and single small structures scattered within the lagoon environments. Our results show that subsidence is characterized by a certain variability at the regional scale with superimposed important local displacements. The movements range from a gentle uplift to subsidence rates of up to 35 mm yr-1. For instance, settlements of 30-35 mm yr-1 have been detected at the three lagoon inlets in correspondence of the MoSE works, and local sinking bowls up to 10 mm yr-1 connected with the construction of new large buildings or restoration works have been measured in the Venice and Chioggia historical centers. Focusing on the city of Venice, the mean subsidence of 1.1 ± 1.0 mm yr-1 confirms the general stability of the historical center. Author(s) 2015. CC Attribution 3.0 License.
BibTeX:
@conference{Tosi2015199,
  author = {Tosi, L. and Strozzi, T. and Da Lio, C. and Teatini, P.},
  title = {Regional and local land subsidence at the Venice coastland by TerraSAR-X PSI},
  booktitle = {Proceedings of the International Association of Hydrological Sciences},
  publisher = {Copernicus GmbH},
  year = {2015},
  volume = {372},
  pages = {199-205},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988457399&doi=10.5194%2fpiahs-372-199-2015&partnerID=40&md5=05c9fb3f9cd1f34a53f3d3a08ad65e6b},
  doi = {10.5194/piahs-372-199-2015}
}
Volksch I, Schwank M, Stahli M and Matzler C (2015), "Relief effects on the L-band emission of a bare soil", Remote Sensing. Vol. 7(11), pp. 14327-14359. MDPI AG.
Abstract: In a combined experimental and model study, we investigated effects of surface topography (relief) on the thermal L-band emission of a sandy soil. To this end, brightness temperatures of two adjacent footprint areas were measured quasi-simultaneously with an L-band radiometer at the observation angle of 55° relative to nadir for one year. One footprint featured a distinct relief in the form of erosion gullies with steep slopes, whereas the surface of the second footprint was smooth. Additionally, hydrometeorological variables, in situ soil moisture and temperature were measured, and digital terrain models of the two scenes were derived from terrestrial laser scanning. A facet model, taking into account the topography of the footprint surfaces as well as the antenna's directivity, was developed and brightness temperatures of both footprints were simulated based on the hydrometeorological and in situ soil data. We found that brightness temperatures of the footprint with the distinct surface relief were increased at horizontal and decreased at vertical polarization with respect to those of the plane footprint. The simulations showed that this is mainly due to modifications of local (facet) observation angles and due to polarization mixing caused by the pronounced relief. Measurements furthermore revealed that brightness temperatures of both areas respond differently to changing ambient conditions indicating differences in their hydrological properties. 2015 by the authors.
BibTeX:
@article{Volksch201514327,
  author = {Volksch, I. and Schwank, M. and Stahli, M. and Matzler, C.},
  title = {Relief effects on the L-band emission of a bare soil},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2015},
  volume = {7},
  number = {11},
  pages = {14327-14359},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84950105743&doi=10.3390%2frs71114327&partnerID=40&md5=513e9bd8f98b6ffb860fb709725f4512},
  doi = {10.3390/rs71114327}
}
Voytenko D, Dixon T, Howat I, Gourmelen N, Lembke C, Werner C, De La Pena S and Oddsson B (2015), "Multi-year observations of Breidamerkurjokull, a marine-terminating glacier in southeastern Iceland, using terrestrial radar interferometry", Journal of Glaciology. Vol. 61(225), pp. 42-54. International Glaciology Society.
Abstract: Terrestrial radar interferometry (TRI) is a new technique for studying ice motion and volume change of glaciers. TRI is especially useful for temporally and spatially dense measurements of highly dynamic glacial termini. We conducted a TRI survey of Breioamerkurjokull, a marine-terminating glacier in Iceland, imaging its terminus near the end of the melt season in 2011, 2012 and 2013. The ice velocities were as high as 5 m d-1, with the fastest velocities near the calving front. Retreat of the glacier over the 3 year observation period was accompanied by strong embayment formation. Iceberg tracking with the radar shows high current velocities near the embayment, probably indicating strong meltwater outflow and mixing with relatively warm lagoon water. 2015, International Glaciology Society. All rights reserved.
BibTeX:
@article{Voytenko201542,
  author = {Voytenko, D. and Dixon, T.H. and Howat, I.M. and Gourmelen, N. and Lembke, C. and Werner, C.L. and De La Pena, S. and Oddsson, B.},
  title = {Multi-year observations of Breidamerkurjokull, a marine-terminating glacier in southeastern Iceland, using terrestrial radar interferometry},
  journal = {Journal of Glaciology},
  publisher = {International Glaciology Society},
  year = {2015},
  volume = {61},
  number = {225},
  pages = {42-54},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84929412802&doi=10.3189%2f2015JoG14J099&partnerID=40&md5=b6ba1f95d3ed3fc6b99e14167ec0b916},
  doi = {10.3189/2015JoG14J099}
}
Wegmüller U, Santoro M, Werner C and Cartus O (2015), "On the estimation and interpretation of sentinel-1 TOPS InSAR coherence", In European Space Agency, (Special Publication) ESA SP. Vol. SP-731 European Space Agency.
Abstract: Sentinel-1 IWS acquisitions can be used for SAR interferometry. In our contribution the focus is on the S1 IWS InSAR coherence. For this we address in a first part the interferogram generation and coherence estimation. Then in a second part we use data examples to get a first impression on the potential of the S1 IWS InSAR coherence for landuse classification and to monitor temporal change.
BibTeX:
@conference{Wegmuller2015a,
  author = {Wegmüller, U. and Santoro, M. and Werner, C. and Cartus, O.},
  editor = {Ouwehand L.},
  title = {On the estimation and interpretation of sentinel-1 TOPS InSAR coherence},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2015},
  volume = {SP-731},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961777762&partnerID=40&md5=f51d24a6d4fcd5cac32f211591fa1210}
}
Wegmüller U, Strozzi T and Werner C (2015), "Earthquake damage mapping using the coherence of persistent scatterers", In European Space Agency, (Special Publication) ESA SP. Vol. SP-731 European Space Agency.
Abstract: After an Earthquake earth observation methods can support the damage assessment. In this contribution we describe an earthquake damage mapping methodology that is based on the coherence of persistent scatterers using a stack of ENVISAT ASAR images. Comparing the damage map generated for Christchurch, New Zeeland, after the Darfield Earthquake on 3-Sep-2010 with liquefaction maps resulting from in-situ assessments indicates a good potential of this methodology in this case.
BibTeX:
@conference{Wegmuller2015c,
  author = {Wegmüller, U. and Strozzi, T. and Werner, C.},
  editor = {Ouwehand L.},
  title = {Earthquake damage mapping using the coherence of persistent scatterers},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  publisher = {European Space Agency},
  year = {2015},
  volume = {SP-731},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961777960&partnerID=40&md5=a9ad296b3b575c70283c05270576cf03}
}
Wegmüller U and Werner C (2015), "Mitigation of thermal expansion phase in persistent scatterer interferometry in an urban environment", In 2015 Joint Urban Remote Sensing Event, JURSE 2015. Institute of Electrical and Electronics Engineers Inc..
Abstract: In an urban environment the differential phase due to thermal expansion of structures is relevant. Uncorrected, the thermal expansion phase leads to a loss of persistent scatterers and increased errors in the deformation time series. In the upper part of tall buildings the thermal expansion phase can vary strongly over time which may result in a complete lack of displacement information if uncompensated. The objective of our work was to estimate and mitigate the thermal expansion phase in our PSI processing. As a result it became possible to include tall buildings into the PSI solution and the accuracy of the solution was improved for all scatterers affected by thermal expansion. 2015 IEEE.
BibTeX:
@conference{wegmuller2015,
  author = {Wegmüller, U. and Werner, C.},
  title = {Mitigation of thermal expansion phase in persistent scatterer interferometry in an urban environment},
  booktitle = {2015 Joint Urban Remote Sensing Event, JURSE 2015},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938823390&doi=10.1109%2fJURSE.2015.7120505&partnerID=40&md5=2150c097bdb26859f4c5a6ad96742d26},
  doi = {10.1109/JURSE.2015.7120505}
}
Wegmüller U, Werner C, Strozzi T, Wiesmann A, Frey O and Santoro M (2015), "Sentinel-1 IWS mode support in the GAMMA software", In Proceedings of the 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2015. , pp. 431-436. Institute of Electrical and Electronics Engineers Inc..
Abstract: First results using the new Sentinel-1 SAR look very promising, but the special interferometrie wide-swath (IWS) data acquired in the FOPS mode makes InSAR processing challenging. Fhe steep azimuth spectra ramp in each burst results in very stringent co-registration requirements. Combining the data of the individual bursts and sub-swaths into consistent mosaics requires careful 'bookkeeping' in the handling of the data and meta data and the large file sizes and high data throughputs require also a good performance. Considering these challenges good support from software is getting increasingly important. In this contribution we describe the Sentinel-1 support in the GAMMA Software, a high-level software package used by researchers, service providers and operational users in their SAR, InSAR and PSI work. 2015 IEEE.
BibTeX:
@conference{Wegmuller2015431,
  author = {Wegmüller, U. and Werner, C. and Strozzi, T. and Wiesmann, A. and Frey, O. and Santoro, M.},
  title = {Sentinel-1 IWS mode support in the GAMMA software},
  booktitle = {Proceedings of the 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2015},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2015},
  pages = {431-436},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957687024&doi=10.1109%2fAPSAR.2015.7306242&partnerID=40&md5=214ec9f71b2f0e46a244cb8eb1811243},
  doi = {10.1109/APSAR.2015.7306242}
}
Wiesmann A, Caduff R and Matzler C (2015), "Terrestrial radar observations of dynamic changes in alpine snow", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 8(7), pp. 3665-3671. Institute of Electrical and Electronics Engineers.
Abstract: Remote sensing of snow with active and passive microwaves on terrestrial, aerial, and satellite platforms has a long tradition. However, the observation of dynamic processes on alpine slopes is difficult due to fixed satellite orbits and consequently given observation geometry and interval and in some cases, also the lack of spatial resolution. Furthermore, the interferometric phase can only be used for displacement measurements if the displacement direction is more or less in the line of sight direction and the observation interval is shorter than the decorrelation time. The use of a terrestrial radar interferometer allows to overcome some of these constraints thanks to the portability of the system, the possibility to make repeat acquisitions in short intervals, and the regional observation capability. In this study, the GPRI (GAMMA portable radar interferometer, [1]) was used that is easily deployable in the field, produces images at meter scale resolution, and allows repeat acquisitions within a minute. Results of two campaigns conducted in the Swiss Alps prove the potential of terrestrial radar to measure rapid and local changes in snow parameters such as changes in the liquid water content and sudden changes in the snowpack due to skiers and avalanches. Using standard interferometric techniques, it was also possible to compute a regional snow displacement map providing information about creeping snow locations, displacement rates, and history. 2015 IEEE.
BibTeX:
@article{Wiesmann20153665,
  author = {Wiesmann, A. and Caduff, R. and Matzler, C.},
  title = {Terrestrial radar observations of dynamic changes in alpine snow},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2015},
  volume = {8},
  number = {7},
  pages = {3665-3671},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939532992&doi=10.1109%2fJSTARS.2015.2400972&partnerID=40&md5=e0bca78bd2783c7e3de23b96e4c70f0a},
  doi = {10.1109/JSTARS.2015.2400972}
}
Blunden J. and Arndt Eds. DS (2014), "State of the climate in 2013", Bulletin of the American Meteorological Society. Vol. 95(7), pp. 1-279. American Meteorological Society.
Abstract: In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Nina or El Nino events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earth's surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series. 2014, American Meteorological Society. All rights reserved.
BibTeX:
@article{Blunden2014S1,
  author = {Blunden, J., and Arndt Eds., D. S.},
  title = {State of the climate in 2013},
  journal = {Bulletin of the American Meteorological Society},
  publisher = {American Meteorological Society},
  year = {2014},
  volume = {95},
  number = {7},
  pages = {1-279},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84910080574&doi=10.1175%2f2014BAMSStateoftheClimate.1&partnerID=40&md5=616bb425324b4ca206a31dfe2282c214},
  doi = {10.1175/2014BAMSStateoftheClimate.1}
}
Caduff R, Kos A, Schlunegger F, McArdell B and Wiesmann A (2014), "Terrestrial radar interferometric measurement of hillslope deformation and atmospheric disturbances in the Illgraben debris-flow catchment, Switzerland", IEEE Geoscience and Remote Sensing Letters. Vol. 11(2), pp. 434-438. Institute of Electrical and Electronics Engineers Inc..
Abstract: We describe a method for rapid identification and precise quantification of slope deformation using a portable radar interferometer. A rockslide with creep-like behavior was identified in the rugged and inaccessible headwaters of the Illgraben debris-flow catchment, located in the Central Swiss Alps. The estimated volume of the moving rock mass was approximately 0.5 × 10 6 m3 with a maximum daily (3-D) displacement rate of 3 mm. Fast scene acquisition in the order of 6 s/scene led to uniquely precise mapping of spatial and temporal variability of atmospheric phase delay. Observations led to a simple qualitative model for prediction of atmospheric disturbances using a simple model for solar radiation, which can be used for advanced campaign planning for short observation periods (hours to days). 2013 IEEE.
BibTeX:
@article{Caduff2014434,
  author = {Caduff, R. and Kos, A. and Schlunegger, F. and McArdell, B.W. and Wiesmann, A.},
  title = {Terrestrial radar interferometric measurement of hillslope deformation and atmospheric disturbances in the Illgraben debris-flow catchment, Switzerland},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  volume = {11},
  number = {2},
  pages = {434-438},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896332706&doi=10.1109%2fLGRS.2013.2264564&partnerID=40&md5=ad25c7cabf1275431315dee44a2ab371},
  doi = {10.1109/LGRS.2013.2264564}
}
Caduff R and Rieke-Zapp D (2014), "Registration and visualisation of deformation maps from terrestrial radar interferometry using photogrammetry and structure from motion", Photogrammetric Record. Vol. 29(146), pp. 167 -186. Blackwell Publishing Ltd.
Abstract: This paper describes a general workflow for the registration of terrestrial radar interferometric data with 3D point clouds derived from terrestrial photogrammetry and structure from motion. After the determination of intrinsic and extrinsic orientation parameters, data obtained by terrestrial radar interferometry were projected on point clouds and then on the initial photographs. Visualisation of slope deformation measurements on photographs provides an easily understandable and distributable information product, especially of inaccessible target areas such as steep rock walls or in rockfall run-out zones. The suitability and error propagation of the referencing steps and final visualisation of four approaches are compared: (a) the classic approach using a metric camera and stereo-image photogrammetry;(b) images acquired with a metric camera, automatically processed using structure from motion; (c) images acquired with a digital compact camera, processed with structure from motion; and (d) a markerless approach, using images acquired with a digital compact camera using structure from motion without artificial ground control points. The usability of the completely markerless approach for the visualisation of high-resolution radar interferometry assists the production of visualisation products for interpretation. 2014 The Remote Sensing and Photogrammetry Society and John Wiley & Sons Ltd.
BibTeX:
@article{Caduff2014167,
  author = {Caduff, R. and Rieke-Zapp, D.},
  title = {Registration and visualisation of deformation maps from terrestrial radar interferometry using photogrammetry and structure from motion},
  journal = {Photogrammetric Record},
  publisher = {Blackwell Publishing Ltd},
  year = {2014},
  volume = {29},
  number = {146},
  pages = {167 -186},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902526662&doi=10.1111%2fphor.12058&partnerID=40&md5=74348c6b53b2302b14d73fdebd807237},
  doi = {10.1111/phor.12058}
}
Canavero M, Murk A, Matzler C, Notel D and Huck J (2014), "Radiometric active indoor imaging in the W-band", Journal of Infrared, Millimeter, and Terahertz Waves. Vol. 35(2), pp. 218-241. Springer New York LLC.
Abstract: Millimeter wave passive imaging systems constitute a good compromise between resolution and penetration depth for a variety of imaging applications. In an outdoor scenario, the cold sky radiation, interacting with the reflectivity characteristics of the targets, constitutes the main source of contrast in the acquired images. In indoor applications such a source is not available, and higher thermal sensitivity is required. Alternatively, one has to provide an artificial illumination to the scene in order to increase its dynamic range. The implementation of an active source for a passive radiometer can, under certain conditions, increase the contrast of the images acquired and add extra information to the measurement. With such a setup, outdoor systems can be used for indoor observations (the absence of cold sky radiation is compensated with active illumination). The subject of our study is to better understand which kind of source and which setup can provide a diffuse illumination over the targets. This topic was investigated by conducting observations of various indoor scenes with two radiometers in the W-Band, using noise and continuous wave (CW) sources as illumination. In this paper we present the results achieved and our conclusions in order to provide an efficient illumination for indoor environment. 2013 Springer Science+Business Media New York.
BibTeX:
@article{Canavero2014218,
  author = {Canavero, M. and Murk, A. and Matzler, C. and Notel, D. and Huck, J.},
  title = {Radiometric active indoor imaging in the W-band},
  journal = {Journal of Infrared, Millimeter, and Terahertz Waves},
  publisher = {Springer New York LLC},
  year = {2014},
  volume = {35},
  number = {2},
  pages = {218-241},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894133339&doi=10.1007%2fs10762-013-0045-9&partnerID=40&md5=39acfd5749c70fd98bc59dc4a15388b8},
  doi = {10.1007/s10762-013-0045-9}
}
Cartus O, Kellndorfer J, Walker W, Franco C, Bishop J, Santos L and Fuentes J (2014), "A national, detailed map of forest aboveground carbon stocks in Mexico", Remote Sensing. Vol. 6(6), pp. 5559-5588. MDPI AG.
Abstract: A spatially explicit map of aboveground carbon stored in Mexico's forests was generated from empirical modeling on forest inventory and spaceborne optical and radar data. Between 2004 and 2007, the Mexican National Forestry Commission (CONAFOR) established a network of  26,000 permanent inventory plots in the frame of their national inventory program, the Inventario Nacional Forestal y de Suelos (INFyS). INFyS data served as model response for spatially extending the field-based estimates of carbon stored in the aboveground live dry biomass to a wall-to-wall map, with 30 × 30 m2 pixel posting using canopy density estimates derived from Landsat, L-Band radar data from ALOS PALSAR, as well as elevation information derived from the Shuttle Radar Topography Mission (SRTM) data set. Validation against an independent set of INFyS plots resulted in a coefficient of determination (R2) of 0.5 with a root mean square error (RMSE) of 14 t·C/ha in the case of flat terrain. The validation for different forest types showed a consistently low estimation bias (&lt; 3 t·C/ha) and R2s in the range of 0.5 except for mangroves (R2 = 0.2). Lower accuracies were achieved for forests located on steep slopes (&gt; 15°) with an R2 of 0.34. A comparison of the average carbon stocks computed from: (a) the map; and (b) statistical estimates from INFyS, at the scale of  650 km2 large hexagons (R2 of 0.78, RMSE of 5 t·C/ha) and Mexican states (R2 of 0.98, RMSE of 1.4 t·C/ha), showed strong agreement. 2014 by the authors.
BibTeX:
@article{Cartus20145559,
  author = {Cartus, O. and Kellndorfer, J. and Walker, W. and Franco, C. and Bishop, J. and Santos, L. and Fuentes, J.M.M.},
  title = {A national, detailed map of forest aboveground carbon stocks in Mexico},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2014},
  volume = {6},
  number = {6},
  pages = {5559-5588},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922724254&doi=10.3390%2frs6065559&partnerID=40&md5=2085474396b1851ac4a9ba4bdfabc3f8},
  doi = {10.3390/rs6065559}
}
Carvalhais N, Forkel M, Khomik M, Bellarby J, Jung M, Migliavacca M, Mu M, Saatchi S, Santoro M, Thurner M, Weber U, Ahrens B, Beer C, Cescatti A, Randerson J and Reichstein M (2014), "Global covariation of carbon turnover times with climate in terrestrial ecosystems", Nature. Vol. 514(7521), pp. 213-217. Nature Publishing Group.
Abstract: The response of the terrestrial carbon cycle to climate change is among the largest uncertainties affecting future climate change projections. The feedback between the terrestrial carbon cycle and climate is partly determined by changes in the turnover time of carbon in land ecosystems, which in turn is an ecosystem property that emerges from the interplay between climate, soil and vegetation type. Here we present a global, spatially explicit and observation-based assessment of whole-ecosystem carbon turnover times that combines new estimates of vegetation and soil organic carbon stocks and fluxes. We find that the overall mean global carbon turnover time is 23-4+7 years (95 per cent confidence interval). On average, carbon resides in the vegetation and soil near the Equator for a shorter time than at latitudes north of 75° north (mean turnover times of 15 and 255 years, respectively). We identify a clear dependence of the turnover time on temperature, as expected from our present understanding of temperature controls on ecosystem dynamics. Surprisingly, our analysis also reveals a similarly strong association between turnover time and precipitation. Moreover, we find that the ecosystem carbon turnover times simulated by state-of-the-art coupled climate/carbon-cycle models vary widely and that numerical simulations, on average, tend to underestimate the global carbon turnover time by 36 per cent. The models show stronger spatial relationships with temperature than do observation-based estimates, but generally do not reproduce the strong relationships with precipitation and predict faster carbon turnover in many semi-arid regions. Our findings suggest that future climate/carbon-cycle feedbacks may depend more strongly on changes in the hydrological cycle than is expected at present and is considered in Earth system models. 2014 Macmillan Publishers Limited. All rights reserved.
BibTeX:
@article{Carvalhais2014213,
  author = {Carvalhais, N. and Forkel, M. and Khomik, M. and Bellarby, J. and Jung, M. and Migliavacca, M. and Mu, M. and Saatchi, S. and Santoro, M. and Thurner, M. and Weber, U. and Ahrens, B. and Beer, C. and Cescatti, A. and Randerson, J.T. and Reichstein, M.},
  title = {Global covariation of carbon turnover times with climate in terrestrial ecosystems},
  journal = {Nature},
  publisher = {Nature Publishing Group},
  year = {2014},
  volume = {514},
  number = {7521},
  pages = {213-217},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908348472&doi=10.1038%2fnature13731&partnerID=40&md5=c103d8571b7179065e61462932534f8d},
  doi = {10.1038/nature13731}
}
Demontoux F, Jonard F, Bircher S, Razafindratsima S, Schwank M, Wigneron J-P and Kerr Y (2014), "Integrated approach for effective permittivity estimation of multi-layered soils at L-Band", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3213-3216. Institute of Electrical and Electronics Engineers Inc..
Abstract: Microwave remote sensing instruments are an adequate way to provide soil moisture information at large scale. Microwave remote sensing data are linked to the electromagnetic properties of soil. In that context, the objective of this study is to develop an integrated approach to estimate effective electromagnetic properties of soils layers at different scale using groundpenetrating radar (GPR), L-band radiometer, dielectric laboratory measurements, modelling approaches and in situ measurements of essential state variables. 2014 IEEE.
BibTeX:
@conference{Demontoux20143213,
  author = {Demontoux, F. and Jonard, F. and Bircher, S. and Razafindratsima, S. and Schwank, M. and Wigneron, J.-P. and Kerr, Y.H.},
  title = {Integrated approach for effective permittivity estimation of multi-layered soils at L-Band},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {3213-3216},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911371844&doi=10.1109%2fIGARSS.2014.6947162&partnerID=40&md5=f584dc4cd5d8ac41ca1883d64d71b237},
  doi = {10.1109/IGARSS.2014.6947162}
}
Dimitrov M, Vanderborght J, Kostov K, Jadoon K, Weihermuller L, Jackson T, Bindlish R, Pachepsky Y, Schwank M and Vereecken H (2014), "Soil hydraulic parameters and surface soil moisture of a tilled bare soil plot inversely derived from l-band brightness temperatures", Vadose Zone Journal. Vol. 13(1)
Abstract: We coupled a radiative transfer model and a soil hydrologic model (HYDRUS 1D) with an optimization routine to derive soil hydraulic parameters, surface roughness, and soil moisture of a tilled bare soil plot using measured brightness temperatures at 1.4 GHz (L-band), rainfall, and potential soil evaporation. The robustness of the approach was evaluated using five 28-d data sets representing different meteorological conditions. We considered two soil hydraulic property models: the unimodal Mualem-van Genuchten and the bimodal model of Durner. Microwave radiative transfer was modeled by three different approaches: the Fresnel equation with depth-averaged dielectric permittivity of either 2-or 5-cm-thick surface layers and a coherent radiative transfer model (CRTM) that accounts for vertical gradients in dielectric permittivity. Brightness temperatures simulated by the CRTM and the 2-cm-layer Fresnel model fitted well to the measured ones. L-band brightness temperatures are therefore related to the dielectric permittivity and soil moisture in a 2-cm-thick surface layer. The surface roughness parameter that was derived from brightness temperatures using inverse modeling was similar to direct estimates from laser profiler measurements. The laboratory-derived water retention curve was bimodal and could be retrieved consistently for the different periods from brightness temperatures using inverse modeling. A unimodal soil hydraulic property function underestimated the hydraulic conductivity near saturation. Surface soil moisture contents simulated using retrieved soil hydraulic parameters were compared with in situ measurements. Depth-specific calibration relations were essential to derive soil moisture from near-surface installed sensors. Soil Science Society of America 5585 Guilford Rd., Madison, WI 53711 USA.
BibTeX:
@article{Dimitrov2014,
  author = {Dimitrov, M. and Vanderborght, J. and Kostov, K.G. and Jadoon, K.Z. and Weihermuller, L. and Jackson, T.J. and Bindlish, R. and Pachepsky, Y. and Schwank, M. and Vereecken, H.},
  title = {Soil hydraulic parameters and surface soil moisture of a tilled bare soil plot inversely derived from l-band brightness temperatures},
  journal = {Vadose Zone Journal},
  year = {2014},
  volume = {13},
  number = {1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893025097&doi=10.2136%2fvzj2013.04.0075&partnerID=40&md5=473736077627d0a64ccfb1a3486a34ed},
  doi = {10.2136/vzj2013.04.0075}
}
Elefante S, Manconi A, Bonano M, De Luca C and Casu F (2014), "Three-dimensional ground displacements retrieved from SAR data in a landslide emergency scenario", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 2400-2403. Institute of Electrical and Electronics Engineers Inc..
Abstract: This work presents the Differential SAR Interferometry and pixel-offset analysis on the event landslide that struck Montescaglioso town (Matera, southern Italy) on December 3rd, 2013. The event occurred after adverse weather conditions that produced a ground displacement of several meters, causing a severe emergency situation. The analysis has shown the presence of two main directions of motion: a major and a minor movement along the South-SouthWest and South-SouthEast directions. The pixel-offset results are well in agreement with both the magnitude and the deformation mechanisms that have been identified and mapped during field observations. 2014 IEEE.
BibTeX:
@conference{Elefante20142400,
  author = {Elefante, S. and Manconi, A. and Bonano, M. and De Luca, C. and Casu, F.},
  title = {Three-dimensional ground displacements retrieved from SAR data in a landslide emergency scenario},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {2400-2403},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911435975&doi=10.1109%2fIGARSS.2014.6946955&partnerID=40&md5=5cf71330f3a6d0a7a00fec48c09cd87e},
  doi = {10.1109/IGARSS.2014.6946955}
}
Fernandez-Moran R, Wigneron J-P, Lopez-Baeza E, Salgado-Hernanz P, Mialon A, Miernecki M, Alyaari A, Parrens M, Schwank M, Wang S, Coll-Pajaron A, Lawrence H and Kerr Y (2014), "Evaluating the impact of roughness in soil moisture and optical thickness retrievals over the VAS area", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1947-1950. Institute of Electrical and Electronics Engineers Inc..
Abstract: In this paper, roughness parameterizations providing best retrievals of soil moisture (SM) at L-band were evaluated. Different parameterizations were tested to find the best correlation R, bias and ubRMSE when comparing retrieved SM and in situ SM measurements carried out at the VAS (Valencia Anchor Station) over a vineyard field. Roughness measurements were always performed after the agricultural practices in the vineyard. These in situ data was used as input of the L-MEB (L-band Microwave Emission of the Biosphere) model, which permits the retrieval of SM and TAU (vegetation optical depth). In addition, a simplified method consisting on the retrieval of a parameter which combines the effects of roughness and TAU was tested. Significantly higher correlation (R=0.86) for SM was found using this method, while the absolute bias (-0.062) and RMSE (0.069) were slightly higher than for other roughness parameterizations. 2014 IEEE.
BibTeX:
@conference{Fernandez-Moran20141947,
  author = {Fernandez-Moran, R. and Wigneron, J.-P. and Lopez-Baeza, E. and Salgado-Hernanz, P.M. and Mialon, A. and Miernecki, M. and Alyaari, A. and Parrens, M. and Schwank, M. and Wang, S. and Coll-Pajaron, A. and Lawrence, H. and Kerr, Y.H.},
  title = {Evaluating the impact of roughness in soil moisture and optical thickness retrievals over the VAS area},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {1947-1950},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911449299&doi=10.1109%2fIGARSS.2014.6946841&partnerID=40&md5=df75f6255d77f8127ea88544866fb2b1},
  doi = {10.1109/IGARSS.2014.6946841}
}
Frey O, Hajnsek I, Wegmüller U and Werner C (2014), "SAR tomography based 3-D point cloud extraction of point-like scatterers in urban areas", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1313-1316. Institute of Electrical and Electronics Engineers Inc..
Abstract: SAR tomography as an extension to persistent scatterer interferometry (PSI) approaches has the potential to improve the level of detail of retrievable information, in particular, in the case of layover scenarios in urban areas. In this paper, a processing approach is sketched that eventually allows for retrieving a 3-D point cloud of point-like scatterers based on subsequent PSI and SAR tomography processing of an interferometric stack of high-resolution spaceborne TerraSAR-X data acquired over the city of Barcelona between the years 2008 and 2012. Experimental results are presented in the form of (1) vertical tomographic slices of high-rise buildings and (2) a 3-D point cloud of a larger district of the city of Barcelona retrieved from the tomograms. 2014 IEEE.
BibTeX:
@conference{Frey20141313,
  author = {Frey, O. and Hajnsek, I. and Wegmüller, U. and Werner, C.L.},
  title = {SAR tomography based 3-D point cloud extraction of point-like scatterers in urban areas},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {1313-1316},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911406703&doi=10.1109%2fIGARSS.2014.6946675&partnerID=40&md5=4458a73b32cd50b278f7494db365761d},
  doi = {10.1109/IGARSS.2014.6946675}
}
Frey O, Siddique M, Hajnsek I, Wegmüller U and Werner C (2014), "Combining SAR tomography and a PSI approach for highresolution 3-D imaging of an urban area", In Proc. European Conf. Synthetic Aperture Radar. Vol. Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR, pp. 1045-1048.
Abstract: Combining persistent scatterer interferometry (PSI) and SAR tomography approaches has the potential to overcome layover scenarios in urban areas and may thus increase the level of detail of differential interferometric measurements of displacements in such environments. In this paper, we report the current status and results of our efforts to integrate SAR tomography into an operational interferometric point target analysis (IPTA) processing tool as an extension to the conventional persistent scatterer interferometry approach. In particular, the PSI and the SAR tomography processing approaches applied are highlighted. In addition, details in the form of tomographic slices of two high-rise buildings are presented as well as a 3-D point cloud reconstruction of parts of the city of Barcelona are shown, as extracted from an interferometric stack of high-resolution stripmap-mode SAR data at X-band acquired by the TerraSAR-X spaceborne SAR sensor. VDE VERLAG GMBH · Berlin · Offenbach, Germany.
BibTeX:
@conference{Frey20141045,
  author = {Frey, O. and Siddique, M.A. and Hajnsek, I. and Wegmüller, U. and Werner, C.L.},
  title = {Combining SAR tomography and a PSI approach for highresolution 3-D imaging of an urban area},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2014},
  volume = {Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR},
  pages = {1045-1048},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991661313&partnerID=40&md5=541a6d9972343965167febd50a535cee}
}
Frey O, Werner C and Wegmüller U (2014), "GPU-based parallelized time-domain back-projection processing for Agile SAR platforms", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1132-1135. Institute of Electrical and Electronics Engineers Inc..
Abstract: Agile SAR platforms such as an automobile require a flexible SAR processing scheme to account for nonlinear sensor trajectories during the synthetic aperture. In this contribution, a parallelized implementation of a time-domain back-projection SAR focusing algorithm based on NVIDIA's CUDA GPU computing framework is presented and discussed using a car-borne SAR data set. The processing performance is assessed using different hardware. In addition, a pre-processing scheme is described that allows for full 3-D motion compensation, yet staying conveniently in conventional slant-range/azimuth geometry of single-look complex SAR images. 2014 IEEE.
BibTeX:
@conference{Frey20141132,
  author = {Frey, O. and Werner, C.L. and Wegmüller, U.},
  title = {GPU-based parallelized time-domain back-projection processing for Agile SAR platforms},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {1132-1135},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911362413&doi=10.1109%2fIGARSS.2014.6946629&partnerID=40&md5=a55e32ef887b0d671fcd7773f9fdde1f},
  doi = {10.1109/IGARSS.2014.6946629}
}
Garcia-Davalillo J, Herrera G, Notti D, Strozzi T and Alvarez-Fernandez I (2014), "DInSAR analysis of ALOS PALSAR images for the assessment of very slow landslides: The Tena Valley case study", Landslides. Vol. 11(2), pp. 225-246. Springer Verlag.
Abstract: In this work we analyse the performance of advanced land observing satellite (ALOS) phased array type L-band syntetic aperture radar (PALSAR) images for mapping and monitoring of very slow landslides using conventional differential interferometry in the Tena Valley (Central Pyrenees, Spain). These results are compared with those retrieved in previous works where multi-band advanced differential interferometric synthetic aperture radar (DInSAR) analysis was performed for the same area using PSI techniques. The study area is largely underlain by slates (ca. 80 %) where large deep-seated very slow earth flows are dominant. The results reveal that DInSAR analysis is able to measure displacements of landslides with a greater spatial coverage than PSI analysis, but for a lower amount of them (nine against 51). Overall, the combination of the DInSAR and multi-band PSI analysis permitted to map and monitor 68 % of the landslides in Tena Valley. From this amount, 63 landslides are considered as active. The main advantage of DInSAR with respect to PSI analysis is the capability to detect faster movements (up to 145 cm year-1) derived from the 46 days interferograms. That is the case of Sextas and La Selva landslides where an acceleration of the moving mass was measured after intense rainfall periods producing major damages to linear infrastructures. The combination of measured displacement from ALOS interferograms, with the observed damages on the A-136 road, was useful to assess the potential damage that could cause these slow movements. In general, it is demonstrated that even though PSI analysis provides a better performance in terms of landslide mapping, L-band DInSAR analysis provides an added value for landslide hazard assessment through radar remote sensing. For this reason it is necessary to encourage the launch of new satellite missions similar to ALOS PALSAR that could operate with shorter revisiting time periods. 2013 Springer-Verlag Berlin Heidelberg.
BibTeX:
@article{GarciaDavalillo2014225,
  author = {Garcia-Davalillo, J.C. and Herrera, G. and Notti, D. and Strozzi, T. and Alvarez-Fernandez, I.},
  title = {DInSAR analysis of ALOS PALSAR images for the assessment of very slow landslides: The Tena Valley case study},
  journal = {Landslides},
  publisher = {Springer Verlag},
  year = {2014},
  volume = {11},
  number = {2},
  pages = {225-246},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897579101&doi=10.1007%2fs10346-012-0379-8&partnerID=40&md5=642c35472d7b027f174b404c79ee8ba8},
  doi = {10.1007/s10346-012-0379-8}
}
Gebhardt S, Wehrmann T, Ruiz M, Maeda P, Bishop J, Schramm M, Kopeinig R, Cartus O, Kellndorfer J, Ressl R, Santos L and Schmidt M (2014), "MAD-MEX: Automatic wall-to-wall land cover monitoring for the mexican REDD-MRV program using all landsat data", Remote Sensing. Vol. 6(5), pp. 3923-3943. MDPI AG.
Abstract: Estimating forest area at a national scale within the United Nations program of Reducing Emissions from Deforestation and Forest Degradation (REDD) is primarily based on land cover information using remote sensing technologies. Timely delivery for a country of a size like Mexico can only be achieved in a standardized and cost-effective manner by automatic image classification. This paper describes the operational land cover monitoring system for Mexico. It utilizes national-scale cartographic reference data, all available Landsat satellite imagery, and field inventory data for validation. Seven annual national land cover maps between 1993 and 2008 were produced. The classification scheme defined 9 and 12 classes at two hierarchical levels. Overall accuracies achieved were up to 76%. Tropical and temperate forest was classified with accuracy up to 78% and 82%, respectively. Although specifically designed for the needs of Mexico, the general process is suitable for other participating countries in the REDD+ program to comply with guidelines on standardization and transparency of methods and to assure comparability. However, reporting of change is ill-advised based on the annual land cover products and a combination of annual land cover and change detection algorithms is suggested. 2014 by the authors.
BibTeX:
@article{Gebhardt20143923,
  author = {Gebhardt, S. and Wehrmann, T. and Ruiz, M.A.M. and Maeda, P. and Bishop, J. and Schramm, M. and Kopeinig, R. and Cartus, O. and Kellndorfer, J. and Ressl, R. and Santos, L.A. and Schmidt, M.},
  title = {MAD-MEX: Automatic wall-to-wall land cover monitoring for the mexican REDD-MRV program using all landsat data},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2014},
  volume = {6},
  number = {5},
  pages = {3923-3943},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901486048&doi=10.3390%2frs6053923&partnerID=40&md5=ecfafa8261a2576851d9dc61d5816446},
  doi = {10.3390/rs6053923}
}
Gladstone R, Schafer M, Zwinger T, Gong Y, Strozzi T, Mottram R, Boberg F and Moore J (2014), "Importance of basal processes in simulations of a surging Svalbard outlet glacier", Cryosphere. Vol. 8(4), pp. 1393-1405. Copernicus GmbH.
Abstract: The outlet glacier of Basin 3 (B3) of Austfonna ice cap, Svalbard, is one of the fastest outlet glaciers in Svalbard, and shows dramatic changes since 1995. In addition to previously observed seasonal summer speed-up associated with the melt season, the winter speed of B3 has accelerated approximately fivefold since 1995. We use the Elmer/Ice full-Stokes model for ice dynamics to infer spatial distributions of basal drag for the winter seasons of 1995, 2008 and 2011. This "inverse" method is based on minimising discrepancy between modelled and observed surface velocities, using satellite remotely sensed velocity fields. We generate steady-state temperature distributions for 1995 and 2011. Frictional heating caused by basal sliding contributes significantly to basal temperatures of the B3 outlet glacier, with heat advection (a longer-timescale process than frictional heating) also being important in the steady state. &lt;br&gt;&lt;br&gt; We present a sensitivity experiment consisting of transient simulations under present-day forcing to demonstrate that using a temporally fixed basal drag field obtained through inversion can lead to thickness change errors of the order of 2 m yearg -1. Hence it is essential to incorporate the evolution of basal processes in future projections of the evolution of B3. Informed by a combination of our inverse method results and previous studies, we hypothesise a system of processes and feedbacks involving till deformation and basal hydrology to explain both the seasonal accelerations (short residence time pooling of meltwater at the ice-till interface) and the ongoing interannual speed-up (gradual penetration of water into the till, reducing till strength). Author(s) 2014. CC Attribution 3.0 License.
BibTeX:
@article{Gladstone20141393,
  author = {Gladstone, R. and Schafer, M. and Zwinger, T. and Gong, Y. and Strozzi, T. and Mottram, R. and Boberg, F. and Moore, J.C.},
  title = {Importance of basal processes in simulations of a surging Svalbard outlet glacier},
  journal = {Cryosphere},
  publisher = {Copernicus GmbH},
  year = {2014},
  volume = {8},
  number = {4},
  pages = {1393-1405},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84905510744&doi=10.5194%2ftc-8-1393-2014&partnerID=40&md5=5bb8460deb1b6ee5441f34b955842305},
  doi = {10.5194/tc-8-1393-2014}
}
Haemmig C, Huss M, Keusen H, Hess J, Wegmüller U, Ao Z and Kulubayi W (2014), "Hazard assessment of glacial lake outburst floods from Kyagar glacier, Karakoram mountains, China", Annals of Glaciology. Vol. 55(66), pp. 34-44. International Glaciology Society.
Abstract: Kyagar glacier is located in the Chinese Karakoram mountains. The glacier tongue entirely blocks the riverbed in the upper Shaksgam valley and impounds a glacial lake, which was the source of several violent and disastrous glacial lake outburst floods (GLOFs). A GLOF early warning system was implemented between 2011 and 2013. We present an integrative analysis of the hazard potential of Kyagar lake, taking into account the ice flow dynamics of Kyagar glacier as well as the recent surface mass-balance response to climate change. Comparison of two high-resolution digital elevation models (DEMs) for the ice dam shows surface lowering rates of &gt;5ma-1 between 2002 and 2011, leading to a significant reduction in the maximum potential lake volume. However, two DEMs covering the entire glacier for the period 2000-10 indicate mass gains in its central part, and flow speed measurements show an acceleration in this region. This pattern of local ice-thickness changes combined with varying ice flow velocities is typical for surge-type glaciers. The velocity of the glacier surface and of the ice dam between 2011 and 2012 are analyzed at high temporal and spatial resolution, based on feature tracking of synthetic aperture radar (SAR) images.
BibTeX:
@article{Haemmig201434,
  author = {Haemmig, C. and Huss, M. and Keusen, H. and Hess, J. and Wegmüller, U. and Ao, Z. and Kulubayi, W.},
  title = {Hazard assessment of glacial lake outburst floods from Kyagar glacier, Karakoram mountains, China},
  journal = {Annals of Glaciology},
  publisher = {International Glaciology Society},
  year = {2014},
  volume = {55},
  number = {66},
  pages = {34-44},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903198522&doi=10.3189%2f2014AoG66A001&partnerID=40&md5=a6d7f40c7fbcd71e2129cbf53b5e1492},
  doi = {10.3189/2014AoG66A001}
}
Jonard F, Demontoux F, Bircher S, Razafindratsima S, Schwank M, Weillermuller L, Lambot S, Wigneron J-P, Kerr Y and Vereecken H (2014), "Electromagnetic characterization of organic-rich soils at the microwave L-band with ground-penetrating radar, radiometry and laboratory measurements", In Proceedings of the 15th International Conference on Ground Penetrating Radar, GPR 2014. , pp. 202-207. Institute of Electrical and Electronics Engineers Inc..
Abstract: Microwave remote sensing of the environment strongly relies on knowledge of the soil electrical properties. In this study, we characterized organic-rich soils using remote ground-penetrating radar (GPR) and radiometer as well as resonant cavity and waveguide reference methods. Organic-rich soil samples were collected from the HOBE (Hydrological Observatory) test site in the Skjern River Catchment (Denmark) and set up at the TERENO (Terrestrial Environmental Observatories) controlled test site in Selhausen (Germany). GPR and L-band radiometer measurements were performed above the soils during two months in order to cover a wide range of soil moisture conditions. GPR data were processed using full-wave inversion based on layered media Green's functions and radiometer data were inverted using a two-stream radiative transfer model for estimating the soil electrical properties. Results were compared to reference measurements carried out at the IMS laboratory (Laboratoire de l'Intégration du Matériau au Système, France) using two different methods, i.e., the small perturbation method with resonant cavity and the waveguide method. Relatively large differences were observed between the different estimation methods for the real part of the relative dielectric permittivity, while reasonable agreement were obtained with respect to its imaginary part. This was attributed to a higher sensitivity of the real part of the relative dielectric permittivity with respect to soil samples heterogeneities. This study provided valuable insights into the electrical characterization of organic soils to improve space-borne remote sensing data products. 2014 IEEE.
BibTeX:
@conference{Jonard2014202,
  author = {Jonard, F. and Demontoux, F. and Bircher, S. and Razafindratsima, S. and Schwank, M. and Weillermuller, L. and Lambot, S. and Wigneron, J.-P. and Kerr, Y. and Vereecken, H.},
  title = {Electromagnetic characterization of organic-rich soils at the microwave L-band with ground-penetrating radar, radiometry and laboratory measurements},
  booktitle = {Proceedings of the 15th International Conference on Ground Penetrating Radar, GPR 2014},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {202-207},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84919624837&doi=10.1109%2fICGPR.2014.6970414&partnerID=40&md5=eed851a6616a82ab977ed472bb3fdb94},
  doi = {10.1109/ICGPR.2014.6970414}
}
Kourkouli P, Wegmüller U, Teatini P, Tosi L, Strozzi T, Wiesmann A and Tansey K (2014), "Ground deformation monitoring over venice lagoon using combined DInSAR/PSI techniques", Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes. , pp. 183-186. Springer International Publishing.
Abstract: Synthetic Aperture Radar Interferometric (InSAR) techniques are widely applied to detect ground displacements caused by both natural and anthropogenic effects. Such techniques are a powerful tool for monitoring the ground motion, however, they have limitations such as temporal and geometrical decorrelation. Persistent Scatterer Interferometry (PSI), a pixel based methodology, has been developed to overcome such constraints. Nevertheless, also with PSI poor spatial coverage is observed in many case studies, especially over natural environments. In this contribution, we propose a methodology using elements from InSAR and PSI techniques in order to improve the spatial coverage with valid information over natural landscapes. For testing the applicability of this methodology, we selected as a test area the Venice Lagoon and specifically an area covered by saltwater marshes. The synergistic approach shows a good potential to achieve a good spatial coverage over the study area. Springer International Publishing Switzerland 2014.
BibTeX:
@book{Kourkouli2014183,
  author = {Kourkouli, P. and Wegmüller, U. and Teatini, P. and Tosi, L. and Strozzi, T. and Wiesmann, A. and Tansey, K.},
  title = {Ground deformation monitoring over venice lagoon using combined DInSAR/PSI techniques},
  journal = {Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes},
  publisher = {Springer International Publishing},
  year = {2014},
  pages = {183-186},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948093675&doi=10.1007%2f978-3-319-08660-6_35&partnerID=40&md5=851762bbc16f04310dd1bb951bcfaf35},
  doi = {10.1007/978-3-319-08660-6_35}
}
Leinss S, Lemmetyinen J, Wiesmann A and Hajnsek I (2014), "Snow structure evolution measured by ground based polarimetric phase differences", In Proc. European Conf. Synthetic Aperture Radar. Vol. Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR, pp. 908-911.
Abstract: Co-polar Phase Differences (CPD) obtained from a fully polarimetric ground based scatterometer operating at 9 to 18 GHz were compared with meteorological data and with spaceborne SAR acquisitions from TerraSAR-X and TanDEM-X. The temporal evolution of the CPD is discussed with respect to the changing microscopic structure of snow. The temporal resolution of 4 hours allowed a precise analysis with respect to snow fall and melt events. Radar reflection measurements were analyzed to gain insight into backscattering properties of dry and wet snow. VDE VERLAG GMBH · Berlin · Offenbach, Germany.
BibTeX:
@conference{Leinss2014908,
  author = {Leinss, S. and Lemmetyinen, J. and Wiesmann, A. and Hajnsek, I.},
  title = {Snow structure evolution measured by ground based polarimetric phase differences},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2014},
  volume = {Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR},
  pages = {908-911},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991705948&partnerID=40&md5=d2b9b967433b2c094496718e1abf6a50}
}
Lemmetyinen J, Pulliainen J, Kontu A, Wiesmann A, Matzler C, Rott H, Voglmeier K, Nagler T, Meta A, Coccia A, Schneebeli M, Proksch M, Davidson M, Schuttemeyer D, Lin C-C and Kern M (2014), "Observations of seasonal snow cover at X and Ku bands during the NoSREx campaign", In Proc. European Conf. Synthetic Aperture Radar. Vol. Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR, pp. 900-903.
Abstract: Results from an experimental campaign, providing measurements of snow microwave backscatter over four winter seasons, are presented. The main dataset consists of tower-based scatterometer observations and coinciding measurements of snow, soil and atmospheric properties. In situ data includes measurements of snow SSA and snow microstructure using computer tomography during dedicated campaign periods. Airborne observations at X and Ku bands were collected at the test site during two seasons using the ESA SnowSAR instrument, covering typical land cover features of the boreal forest zone. We present the main findings of the experiment, relating the physical properties of snow to the measured backscatter. The tower based observations are applied to study the temporal evolution of the backscatter signal, including effects such as metamorphism of snow microstructure. The airborne data are used to study the effects of varying land cover on snow backscatter signatures, as well as to demonstrate the retrieval of Snow Water Equivalent from X/Ku band backscatter observations using the retrieval concept developed for CoReH2O. VDE VERLAG GMBH · Berlin · Offenbach, Germany.
BibTeX:
@conference{Lemmetyinen2014900,
  author = {Lemmetyinen, J. and Pulliainen, J. and Kontu, A. and Wiesmann, A. and Matzler, C. and Rott, H. and Voglmeier, K. and Nagler, T. and Meta, A. and Coccia, A. and Schneebeli, M. and Proksch, M. and Davidson, M. and Schuttemeyer, D. and Lin, C.-C. and Kern, M.},
  title = {Observations of seasonal snow cover at X and Ku bands during the NoSREx campaign},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  year = {2014},
  volume = {Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR},
  pages = {900-903},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991636692&partnerID=40&md5=3b8ce3d0da4e22226ae775999e5a6f86}
}
Lollino G, Manconi A, Locat J, Huang Y and Artigas M (2014), "Engineering Geology for Society and Territory-Volume 4: Marine and Coastal Processes", Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes. , pp. 1-235. Springer International Publishing.
Abstract: This book is one out of 8 IAEG XII Congress volumes, and deals with the processes occurring on the coastal zone, which represents a critical interface between land and sea, as the contribution of the ocean to the provision of energy and mineral resources will likely increase in the coming decades. Several related topics fit into this volume, such as: coastal developments and infrastructures; dredging and beach re-nourishment; sediment erosion, transport and accumulation; geohazard assessment; seafloor uses; seabed mapping; exploration and exploitation of the seafloor, of the sub-seafloor, and of marine clean energies and climatic and anthropogenic impacts on coastal and marine environments. Examples of specific themes are coastal management and shore protection, taking into account storm-related events and natural and anthropogenic changes in the relative sea level, planning of waste disposal, remedial works for coastal pollution, seafloor pipeline engineering, slope stability analysis, or tsunami propagation and flooding. The Engineering Geology for Society and Territory volumes of the IAEG XII Congress held in Torino from September 15-19, 2014, analyze the dynamic role of engineering geology in our changing world and build on the four main themes of the congress: environment, processes, issues and approaches. The congress topics and subject areas of the 8 IAEG XII Congress volumes are: 1. Climate Change and Engineering Geology 2. Landslide Processes River Basins 3. Reservoir Sedimentation and Water Resources 4. Marine and Coastal Processes Urban Geology 5. Sustainable Planning and Landscape Exploitation 6. Applied Geology for Major Engineering Projects 7. Education, Professional Ethics and Public Recognition of Engineering Geology 8. Preservation of Cultural Heritage. Springer International Publishing Switzerland 2014.
BibTeX:
@book{Lollino20141,
  author = {Lollino, G. and Manconi, A. and Locat, J. and Huang, Y. and Artigas, M.C.},
  title = {Engineering Geology for Society and Territory-Volume 4: Marine and Coastal Processes},
  journal = {Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes},
  publisher = {Springer International Publishing},
  year = {2014},
  pages = {1-235},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948096390&doi=10.1007%2f978-3-319-08660-6&partnerID=40&md5=2ff6f9abccd3d7a5789e54ecc57dec7f},
  doi = {10.1007/978-3-319-08660-6}
}
Magnard C, Frioud M, Small D, Brehm T, Essen H and Meier E (2014), "Processing of MEMPHIS Ka-band multibaseline interferometric SAR data: From raw data to digital surface models", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 7(7), pp. 2927-2941. Institute of Electrical and Electronics Engineers.
Abstract: MEMPHIS is an experimental millimeter-wave synthetic aperture radar (SAR) system that acquires cross-track multibaseline interferometric data at high resolution in a single pass, using four receive horns. In this paper, we present the SAR system and navigation data, and propose a processing chain from the raw data input to a digital surface model (DSM) output. This processing chain includes full bandwidth reconstruction of the stepped-frequency SAR data, azimuth focusing with an Extended Omega-K algorithm, generation of interferograms for each available baseline, phase unwrapping using the multibaseline data, and phase-to-height conversion. The hardware and processing chain were validated through the analysis of experimental Ka-band data. The SAR image resolution was measured with point targets and found to be &2 and ∼15% coarser than the theoretical value in range and azimuth, respectively. The geolocation accuracy was typically better than 0.1 m in range and 0.2 m in azimuth. Observed depression angle-dependent interferometric phase errors were successfully removed using a correction function derived from the InSAR data. Investigation of the interferometric phase noise showed the utility of a multibaseline antenna setup; the number of looks and filter size used for the DSM generation were also derived from this analysis. The results showed that in grassland areas, the height difference between the ∼2m-resolution InSAR DSMs and the reference ALS models was 0±0.25 m. 2014 IEEE.
BibTeX:
@article{Magnard20142927,
  author = {Magnard, C. and Frioud, M. and Small, D. and Brehm, T. and Essen, H. and Meier, E.},
  title = {Processing of MEMPHIS Ka-band multibaseline interferometric SAR data: From raw data to digital surface models},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2014},
  volume = {7},
  number = {7},
  pages = {2927-2941},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906946405&doi=10.1109%2fJSTARS.2014.2315896&partnerID=40&md5=c4792ca4c3b46b9fd59b0f1ff85f421e},
  doi = {10.1109/JSTARS.2014.2315896}
}
Manconi A, Casu F, Ardizzone F, Bonano M, Cardinali M, De Luca C, Gueguen E, Marchesini I, Parise M, Vennari C, Lanari R and Guzzetti F (2014), "Brief communication: Rapid mapping of landslide events: The 3 December 2013 Montescaglioso landslide, Italy", Natural Hazards and Earth System Sciences. Vol. 14(7), pp. 1835-1841. Copernicus GmbH.
Abstract: We present an approach to measure 3-D surface deformations caused by large, rapid-moving landslides using the amplitude information of high-resolution, X-band synthetic aperture radar (SAR) images. We exploit SAR data captured by the COSMO-SkyMed satellites to measure the deformation produced by the 3 December 2013 Montescaglioso landslide, southern Italy. The deformation produced by the deep-seated landslide exceeded 10 m and caused the disruption of a main road, a few homes and commercial buildings. The results open up the possibility of obtaining 3-D surface deformation maps shortly after the occurrence of large, rapid-moving landslides using high-resolution SAR data. 2014 Author(s).
BibTeX:
@article{Manconi20141835,
  author = {Manconi, A. and Casu, F. and Ardizzone, F. and Bonano, M. and Cardinali, M. and De Luca, C. and Gueguen, E. and Marchesini, I. and Parise, M. and Vennari, C. and Lanari, R. and Guzzetti, F.},
  title = {Brief communication: Rapid mapping of landslide events: The 3 December 2013 Montescaglioso landslide, Italy},
  journal = {Natural Hazards and Earth System Sciences},
  publisher = {Copernicus GmbH},
  year = {2014},
  volume = {14},
  number = {7},
  pages = {1835-1841},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84905003484&doi=10.5194%2fnhess-14-1835-2014&partnerID=40&md5=4e667075151cfccde696af2441e45ff2},
  doi = {10.5194/nhess-14-1835-2014}
}
McMillan M, Shepherd A, Gourmelen N, Dehecq A, Leeson A, Ridout A, Flament T, Hogg A, Gilbert L, Benham T, Van Den Broeke M, Dowdeswell J, Fettweis X, Noël B and Strozzi T (2014), "Rapid dynamic activation of a marine-based Arctic ice cap", Geophysical Research Letters. Vol. 41(24), pp. 8902-8909. Blackwell Publishing Ltd.
Abstract: We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two decades, the sector ice discharge has increased 45-fold, the velocity regime has switched from predominantly slow (  101 m/yr) to fast (  103 m/yr) flow, and rates of ice thinning have exceeded 25 m/yr. At the time of widespread dynamic activation, parts of the terminus may have been near floatation. Subsequently, the imbalance has propagated 50 km inland to within 8 km of the ice cap summit. Our observations demonstrate the ability of slow-flowing ice to mobilize and quickly transmit the dynamic imbalance inland; a process that we show has initiated rapid ice loss to the ocean and redistribution of ice mass to locations more susceptible to melt, yet which remains poorly understood. Key Points Recent dynamic activation of a formerly slow-flowing marine Arctic ice capImbalance has spread 50 km inland to within 8 km of the ice cap summitIce discharge has increased 45-fold, and thinning rates have exceeded 25 m/yr 2014. The Authors.
BibTeX:
@article{McMillan20148902,
  author = {McMillan, M. and Shepherd, A. and Gourmelen, N. and Dehecq, A. and Leeson, A. and Ridout, A. and Flament, T. and Hogg, A. and Gilbert, L. and Benham, T. and Van Den Broeke, M. and Dowdeswell, J.A. and Fettweis, X. and Noël, B. and Strozzi, T.},
  title = {Rapid dynamic activation of a marine-based Arctic ice cap},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2014},
  volume = {41},
  number = {24},
  pages = {8902-8909},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921844855&doi=10.1002%2f2014GL062255&partnerID=40&md5=010511d9290aa41e02587c98f7406528},
  doi = {10.1002/2014GL062255}
}
Miernecki M, Wigneron J-P, Lopez-Baeza E, Kerr Y, De Jeu R, De Lannoy G, Jackson T, O'Neill P, Schwank M, Moran R, Bircher S, Lawrence H, Mialon A, Al Bitar A and Richaume P (2014), "Comparison of SMOS and SMAP soil moisture retrieval approaches using tower-based radiometer data over a vineyard field", Remote Sensing of Environment. Vol. 154(1), pp. 89-101. Elsevier Inc..
Abstract: The objective of this study was to compare several approaches to soil moisture (SM) retrieval using l-band microwave radiometry. The comparison was based on a brightness temperature (TB) data set acquired since 2010 by the L-band radiometer ELBARA-II over a vineyard field at the Valencia Anchor Station (VAS) site. ELBARA-II, provided by the European Space Agency (ESA) within the scientific program of the SMOS (Soil Moisture and Ocean Salinity) mission, measures multiangular TB data at horizontal and vertical polarization for a range of incidence angles (30°-60°). Based on a three year data set (2010-2012), several SM retrieval approaches developed for spaceborne missions including AMSR-E (Advanced Microwave Scanning Radiometer for EOS), SMAP (Soil Moisture Active Passive) and SMOS were compared. The approaches include: the Single Channel Algorithm (SCA) for horizontal (SCA-H) and vertical (SCA-V) polarizations, the Dual Channel Algorithm (DCA), the Land Parameter Retrieval Model (LPRM) and two simplified approaches based on statistical regressions (referred to as 'Mattar' and 'Saleh'). Time series of vegetation indices required for three of the algorithms (SCA-H, SCA-V and 'Mattar') were obtained from MODIS observations. The SM retrievals were evaluated against reference SM values estimated from a multiangular 2-Parameter inversion approach. As no in situ SM data was used, the evaluation made here is relative to the use of this specific reference data set. The results obtained with the current base line algorithms developed for SMAP (SCA-H and -V) are in very good agreement with the 'reference' SM data set derived from the multi-angular observations (R2≈0.90, RMSE varying between 0.035 and 0.056m3/m3 for several retrieval configurations). This result showed that, provided the relationship between vegetation optical depth and a remotely-sensed vegetation index can be calibrated, the SCA algorithms can provide results very close to those obtained from multi-angular observations in this study area. The approaches based on statistical regressions provided similar results and the best accuracy was obtained with the 'Saleh' methods based on either bi-angular or bipolarization observations (R2≈0.93, RMSE≈0.035m3/m3). The LPRM and DCA algorithms were found to be slightly less successful in retrieving the 'reference' SM time series (R2≈0.75, RMSE≈0.055m3/m3). However, the two above approaches have the great advantage of not requiring any model calibrations previous to the SM retrievals. 2014 Elsevier Inc.
BibTeX:
@article{Miernecki201489,
  author = {Miernecki, M. and Wigneron, J.-P. and Lopez-Baeza, E. and Kerr, Y. and De Jeu, R. and De Lannoy, G.J.M. and Jackson, T.J. and O'Neill, P.E. and Schwank, M. and Moran, R.F. and Bircher, S. and Lawrence, H. and Mialon, A. and Al Bitar, A. and Richaume, P.},
  title = {Comparison of SMOS and SMAP soil moisture retrieval approaches using tower-based radiometer data over a vineyard field},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2014},
  volume = {154},
  number = {1},
  pages = {89-101},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908100906&doi=10.1016%2fj.rse.2014.08.002&partnerID=40&md5=c1587e09497666ec50112e095a48472e},
  doi = {10.1016/j.rse.2014.08.002}
}
Pantze A, Santoro M and Fransson J (2014), "Change detection of boreal forest using bi-temporal ALOS PALSAR backscatter data", Remote Sensing of Environment. Vol. 155, pp. 120-128. Elsevier Inc..
Abstract: Long-wavelength Synthetic Aperture Radar (SAR) satellite systems have the potential to increase the efficiency of forest mapping and monitoring, which today are based primarily on optical satellite systems. Here, we evaluate the effectiveness of using L-band SAR satellite images to detect and delineate clear-cuts in Swedish boreal forest. A set of computationally efficient techniques are combined in a fully automated unsupervised bi-temporal change detection approach that detects changes in SAR backscatter intensities. For radiometric normalization and initial change classification, we propose an iterative procedure consisting of successive polynomial based histogram matching and thresholding. Recently proposed methods for automatic SAR amplitude ratio thresholding and final change classification are adopted. The latter is a Markov random field based change detection method that exploits both spectral and spatial information from one or multiple SAR polarization channels. The change detection approach was applied to SAR images from the Japanese Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) acquired in Fine Beam Dual (FBD) mode (HH- and HV-polarizations) with a pixel size of 20. m (path data). Clear-cuts that took place between image acquisitions were clearly detected, and most errors were due to imperfect delineations of clear-cut edges. Pixel-wise clear-cut detection accuracies above 90% could be reached, with false alarm rates of approximately 10% or less. The results indicate that ALOS PALSAR path data are well suited for operational clear-cut detection in Swedish boreal forest. 2014 Elsevier Inc.
BibTeX:
@article{Pantze2014120,
  author = {Pantze, A. and Santoro, M. and Fransson, J.E.S.},
  title = {Change detection of boreal forest using bi-temporal ALOS PALSAR backscatter data},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2014},
  volume = {155},
  pages = {120-128},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84909585663&doi=10.1016%2fj.rse.2013.08.050&partnerID=40&md5=d260295b4155adf748dbc9135d0151eb},
  doi = {10.1016/j.rse.2013.08.050}
}
Rautiainen K, Lemmetyinen J, Schwank M, Kontu A, Ménard C, Matzler C, Drusch M, Wiesmann A, Ikonen J and Pulliainen J (2014), "Detection of soil freezing from L-band passive microwave observations", Remote Sensing of Environment. Vol. 147, pp. 206-218. Elsevier Inc..
Abstract: We present a novel algorithm for detecting seasonal soil freezing processes using L-band microwave radiometry. L-band is the optimal choice of frequency for the monitoring of soil freezing, due to the inherent high contrast of the microwave signature between the frozen and thawed states of the soil medium. Dual-polarized observations of L-band brightness temperature at a range of observation angles were collected from a tower-based instrument, and evaluated against ancillary information on soil and snow properties over four winter seasons. During the first three winter periods the measurement site was located over mineral soil on a forest clearing, for the fourth winter the instrument was moved to a wetland site. Both sites are located in Sodankyla, Northern Finland. The test sites represent two environments typical for the northern boreal forest zone. The data were applied to derive an empirical relation between the onset and progress of soil freezing and the observed passive L-band signature. A retrieval algorithm was developed using the observations at the forest opening site. The algorithm exploits the perceived change in brightness temperature and the change in the relative difference between the signatures at horizontal and vertical polarization. With the collected experimental dataset, these features were linked optimally to the progress of soil freezing by choice of observation angle, polarization and temporal averaging. The wetland site observations provided the first opportunity for demonstrating the developed algorithm over a different soil type, giving a first estimate of the algorithm performance over larger heterogeneous targets. The future objective is to adapt the algorithm to L-band satellite observations. The present study is highly relevant for the development of freeze-thaw algorithms from current and future L-band satellite missions such as SMOS and SMAP. 2014 Elsevier Inc.
BibTeX:
@article{Rautiainen2014206,
  author = {Rautiainen, K. and Lemmetyinen, J. and Schwank, M. and Kontu, A. and Ménard, C.B. and Matzler, C. and Drusch, M. and Wiesmann, A. and Ikonen, J. and Pulliainen, J.},
  title = {Detection of soil freezing from L-band passive microwave observations},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2014},
  volume = {147},
  pages = {206-218},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897069346&doi=10.1016%2fj.rse.2014.03.007&partnerID=40&md5=7533f0105adf73c37e0cecdc2f232207},
  doi = {10.1016/j.rse.2014.03.007}
}
Santoro M and Wegmüller U (2014), "Multi-temporal synthetic aperture radar metrics applied to map open water bodies", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 7(8), pp. 3225-3238. Institute of Electrical and Electronics Engineers.
Abstract: Multi-temporal synthetic aperture radar (SAR) metrics are assessed to map open water bodies. High temporal variability and low minimum value in a time series of Envisat Advanced SAR (ASAR) Wide Swath Mode (WSM) backscatter measurements characterize open water bodies with respect to other land cover types. Confusion occurs in the case of steep terrain (slope angle > 10°), less than 10 backscatter observations and for mixed pixels with a water fraction. The behavior of the two SAR multi-temporal metrics is consistent at six study areas in Europe and Central Siberia. A simple thresholding algorithm applied to the multi-temporal SAR metrics to map open water bodies performs with overall accuracies above 90% in the case of pure pixels of water or land. The accuracy decreases when mixed pixels are accounted for in the reference dataset and for increasing land fraction in the reference samples. An overall accuracy of approximately 80% was obtained for a 50% threshold of the water fraction. Omissions of water areas occur mostly along shorelines. Specific conditions of the land surface can distort the minimum, causing commission in the water class. The use of a low order rank or percentile instead of the lowest backscatter value can reduce such commission error. 2013 IEEE.
BibTeX:
@article{Santoro20143225,
  author = {Santoro, M. and Wegmüller, U.},
  title = {Multi-temporal synthetic aperture radar metrics applied to map open water bodies},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2014},
  volume = {7},
  number = {8},
  pages = {3225-3238},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907972496&doi=10.1109%2fJSTARS.2013.2289301&partnerID=40&md5=93c0f29b0a29d5c7666060e2e0550642},
  doi = {10.1109/JSTARS.2013.2289301}
}
Santoro M, Wegmüller U, Fransson J and Schmullius C (2014), "Regional mapping of forest growing stock volume with multitemporal ALOS PALSAR backscatter", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 2313-2316. Institute of Electrical and Electronics Engineers Inc..
Abstract: The paper presents advances in regional mapping of forest growing stock volume (GSV, unit: m3/ha) using multitemporal ALOS PALSAR images. For this, an approach based on the Water Cloud Model has been used. Fine Beam Dual (FBD) and Wide Beam (WB) mode backscatter data acquired during 2010 were inverted to GSV; the individual GSV estimates were then combined to form an improved estimate. Examples of regional mapping for the boreal, temperate and tropical zone are here presented. Estimates were obtained at 25 m resolution using FBD data only and at 75 m combining multi-looked FBD estimates and WB estimates. The inclusion of multi-temporal WB data served to improve the spatial characterization of GSV. At pixel level, the discrepancy with respect to other estimates from Earth Observation data was large (relative RMSE ∼ 90%). Aggregation to lower resolution (e.g., 1 km) increased the agreement and a relative RMSE mostly below 30% was obtained. 2014 IEEE.
BibTeX:
@conference{Santoro20142313,
  author = {Santoro, M. and Wegmüller, U. and Fransson, J.E.S. and Schmullius, C.},
  title = {Regional mapping of forest growing stock volume with multitemporal ALOS PALSAR backscatter},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {2313-2316},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911366995&doi=10.1109%2fIGARSS.2014.6946933&partnerID=40&md5=dbc5ad8fdb6469a7d9e87f9b26df4935},
  doi = {10.1109/IGARSS.2014.6946933}
}
Schafer M, Gillet-Chaulet F, Gladstone R, Pettersson R, Pohjola V, Strozzi T and Zwinger T (2014), "Assessment of heat sources on the control of fast flow of Vestfonna ice cap, Svalbard", Cryosphere. Vol. 8(5), pp. 1951-1973. Copernicus GmbH.
Abstract: Understanding the response of fast flowing ice streams or outlet glaciers to changing climate is crucial in order to make reliable projections of sea level change over the coming decades. Motion of fast outlet glaciers occurs largely through basal motion governed by physical processes at the glacier bed, which are not yet fully understood. Various subglacial mechanisms have been suggested for fast flow but common to most of the suggested processes is the requirement of presence of liquid water, and thus temperate conditions.

We use a combination of modelling, field, and remote observations in order to study links between different heat sources, the thermal regime and basal sliding in fast flowing areas on Vestfonna ice cap. A special emphasis lies on Franklinbreen, a fast flowing outlet glacier which has been observed to accelerate recently. We use the ice flow model Elmer/Ice including a Weertman type sliding law and a Robin inverse method to infer basal friction parameters from observed surface velocities. Firn heating, i.e. latent heat release through percolation of melt water, is included in our model; its parameterisation is calibrated with the temperature record of a deep borehole. We found that strain heating is negligible, whereas friction heating is identified as one possible trigger for the onset of fast flow. Firn heating is a significant heat source in the central thick and slow flowing area of the ice cap and the essential driver behind the ongoing fast flow in all outlets.

Our findings suggest a possible scenario of the onset and maintenance of fast flow on the Vestfonna ice cap based on thermal processes and emphasise the role of latent heat released through refreezing of percolating melt water for fast flow. However, these processes cannot yet be captured in a temporally evolving sliding law. In order to simulate correctly fast flowing outlet glaciers, ice flow models not only need to account fully for all heat sources, but also need to incorporate a sliding law that is not solely based on the basal temperature, but also on hydrology and/or sediment physics. 2014 Author(s).
BibTeX:
@article{Schafer20141951,
  author = {Schafer, M. and Gillet-Chaulet, F. and Gladstone, R. and Pettersson, R. and Pohjola, V.A. and Strozzi, T. and Zwinger, T.},
  title = {Assessment of heat sources on the control of fast flow of Vestfonna ice cap, Svalbard},
  journal = {Cryosphere},
  publisher = {Copernicus GmbH},
  year = {2014},
  volume = {8},
  number = {5},
  pages = {1951-1973},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908246957&doi=10.5194%2ftc-8-1951-2014&partnerID=40&md5=561286a185736e52420687bf8febe4df},
  doi = {10.5194/tc-8-1951-2014}
}
Schwank M, Rautiainen K, Matzler C, Stahli M, Lemmetyinen J, Pulliainen J, Vehvilainen J, Kontu A, Ikonen J, Ménard C, Drusch M, Wiesmann A and Wegmüller U (2014), "Model for microwave emission of a snow-covered ground with focus on L band", Remote Sensing of Environment. Vol. 154(1), pp. 180-191. Elsevier Inc..
Abstract: Passive L-band (1-2 GHz) observables are sensitive to surface soil moisture and ocean salinity, which is the core of the "soil moisture and ocean salinity" (SMOS) mission of the European Space Agency (ESA). This work investigatesmicrowave emission processes that are important to link L-band brightness temperatureswith soil freeze/ thaw states and the presence and the state of snow. To this end, a ground snowradiative transfer (GS RT) model has been developed on the basis of the "Microwave EmissionModel of Layered Snowpacks" (MEMLS). Ourmodel sensitivity study revealed that L-band emission of a freezing ground can be affected significantly by dry snow, which has beenmostly disregarded in previous studies. Simulations suggest that even dry snowwithmostly negligible absorption at the L-band can impact L-band emission ofwinter landscapes significantly. We found that impedancematching and refraction caused by a dry snowpack can increase or decrease L-band emission depending on the polarization and the observation angle. Based on the performed sensitivity study, these RT processes can be compensatory at vertical polarization and the observation angle of 50°. This suggests the use of vertical polarized brightness temperatures measured at around 50° in order to achieve segregated information on soil-frost. Furthermore, our simulations demonstrate a significant sensitivity of L-band emission at horizontal polarization with respect to the density of the lowest snow layer as the result of refraction and impedance matching by the snowpack. 2014 Elsevier Inc.
BibTeX:
@article{Schwank2014180,
  author = {Schwank, M. and Rautiainen, K. and Matzler, C. and Stahli, M. and Lemmetyinen, J. and Pulliainen, J. and Vehvilainen, J. and Kontu, A. and Ikonen, J. and Ménard, C.B. and Drusch, M. and Wiesmann, A. and Wegmüller, U.},
  title = {Model for microwave emission of a snow-covered ground with focus on L band},
  journal = {Remote Sensing of Environment},
  publisher = {Elsevier Inc.},
  year = {2014},
  volume = {154},
  number = {1},
  pages = {180-191},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84927710881&doi=10.1016%2fj.rse.2014.08.029&partnerID=40&md5=34757c9d93eb8c5b3e315da91ede50d3},
  doi = {10.1016/j.rse.2014.08.029}
}
Tanase M, Santoro M, Aponte C and De La Riva J (2014), "Polarimetric properties of burned forest areas at C- and L-band", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. Vol. 7(1), pp. 267-276.
Abstract: Fully polarimetric C- and L-band synthetic aperture radar (SAR) data have been investigated to determine the relationship between polarimetric target decomposition components and forest burn severity over two sites located in a Mediterranean environment. The dependence of the polarimetric decomposition metrics on SAR acquisition geometry and environmental conditions was also analyzed at C-band. Multiple linear regression models with interactions (i.e., the incidence angle was included as a predictor variable and its interaction with the radar metrics was accounted for as a multiplicative effect) were used to quantify burn severity retrieval accuracy. According to our experiment, we found that for steep SAR acquisition geometries C-band polarimetric components related to surface scattering mechanisms had increased sensitivity to burn severity levels, while for datasets acquired with more grazing geometries the polarimetric components related to volume scattering and dihedral scattering mechanisms were more correlated with burn severity levels. At L-band only volume and dihedral scattering related decomposition components provided significant relationships with burn severity levels. Relatively low burn severity estimation errors (less than 20% of burn severity range) were obtained for all datasets, with L-band data presenting the highest sensitivity to fire effects. Using a single regression model provided sufficient accuracy for burn severity estimation when taking into account the local incidence angle. The use of fully polarimetric data improved the estimation accuracy of forest burn severity with respect to backscatter intensities by a small margin for our study sites. However, since backscatter intensity metrics already provide high retrieval accuracies, whatever improvement was bound to be low. 2013 IEEE.
BibTeX:
@article{Tanase2014267,
  author = {Tanase, M.A. and Santoro, M. and Aponte, C. and De La Riva, J.},
  title = {Polarimetric properties of burned forest areas at C- and L-band},
  journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
  year = {2014},
  volume = {7},
  number = {1},
  pages = {267-276},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84891749100&doi=10.1109%2fJSTARS.2013.2261053&partnerID=40&md5=be1d0840aaadfe680560bd4ca7a21541},
  doi = {10.1109/JSTARS.2013.2261053}
}
Teatini P, Tosi L and Strozzi T (2014), "Capability of X-band persistent scatterer interferometry to monitor land subsidence in the Venice lagoon", Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes. , pp. 175-178. Springer International Publishing.
Abstract: Land subsidence is a widespread phenomenon, particularly relevant to natural areas such as wetlands, deltas, and lagoons characterized by low elevation with respect to the mean sea level. The possibility of mapping vertical displacements of large coastal lowlying areas at very high resolution began in the 2000s with the development of the Persistent Scatterer Interferometry (PSI). This synthetic aperture radar (SAR)-based methodology detects the displacements of man-made structures within the landscape, such as buildings, utility poles, and roadways. Experience with SAR data of the European Remote Sensing satellites ERS-1, ERS-2, and ENVISAT, characterized by a spatial resolution of about 20 m, a wavelength λ of the signal of 5.66 cm (C-band), and a repeat cycle of 35 days, suggested that persistent targets can be identified only for a fraction of the number of buildings or infrastructures larger than a few meters, and the precise position of the SAR scatterers are difficult to discern. With a very-high image resolution (about 3 m) and an acquisition repeatability never available in the past (between 11 and 16 days), the new generation of X-band (λ = 3.11 cm) SAR satellites has improved significantly the possibility of monitoring the movements of single small structures scattered within rural and natural environments. In this work, we present the PSI outcome in the Venice Lagoon using the German TerraSAR-X and the Italian COSMOSkyMed satellites. The investigated period covers the time interval 2008-2011. The outcomes of the two X-band analyses are compared both at the regional and the local scale in terms of target coverage and distribution and subsidence rates. Springer International Publishing Switzerland 2014.
BibTeX:
@book{Teatini2014175,
  author = {Teatini, P. and Tosi, L. and Strozzi, T.},
  title = {Capability of X-band persistent scatterer interferometry to monitor land subsidence in the Venice lagoon},
  journal = {Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes},
  publisher = {Springer International Publishing},
  year = {2014},
  pages = {175-178},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948104123&doi=10.1007%2f978-3-319-08660-6_33&partnerID=40&md5=b67bd6653d9f0388fd36baf4da04fb27},
  doi = {10.1007/978-3-319-08660-6_33}
}
Thurner M, Beer C, Santoro M, Carvalhais N, Wutzler T, Schepaschenko D, Shvidenko A, Kompter E, Ahrens B, Levick S and Schmullius C (2014), "Carbon stock and density of northern boreal and temperate forests", Global Ecology and Biogeography. Vol. 23(3), pp. 297-310.
Abstract: Aim: To infer a forest carbon density map at 0.01° resolution from a radar remote sensing product for the estimation of carbon stocks in Northern Hemisphere boreal and temperate forests. Location: The study area extends from 30°N to 80°N, covering three forest biomes - temperate broadleaf and mixed forests (TBMF), temperate conifer forests (TCF) and boreal forests (BFT) - over three continents (North America, Europe and Asia). Methods: This study is based on a recently available growing stock volume (GSV) product retrieved from synthetic aperture radar data. Forest biomass and spatially explicit uncertainty estimates were derived from the GSV using existing databases of wood density and allometric relationships between biomass compartments (stem, branches, roots, foliage). We tested the resultant map against inventory-based biomass data from Russia, Europe and the USA prior to making intercontinent and interbiome carbon stock comparisons. Results: Our derived carbon density map agrees well with inventory data at regional scales (r2=0.70-0.90). While 40.7±15.7 petagram of carbon (PgC) are stored in BFT, TBMF and TCF contain 24.5±9.4PgC and 14.5±4.8 PgC, respectively. In terms of carbon density, we found 6.21±2.07kgC m-2 retained in TCF and 5.80±2.21kgC m-2 in TBMF, whereas BFT have a mean carbon density of 4.00±1.54kgC m-2. Indications of a higher carbon density in Europe compared with the other continents across each of the three biomes could not be proved to be significant. Main conclusions: The presented carbon density and corresponding uncertainty map give an insight into the spatial patterns of biomass and stand as a new benchmark to improve carbon cycle models and carbon monitoring systems. In total, we found 79.8±29.9PgC stored in northern boreal and temperate forests, with Asian BFT accounting for 22.1±8.3PgC. 2013 The Authors.
BibTeX:
@article{Thurner2014297,
  author = {Thurner, M. and Beer, C. and Santoro, M. and Carvalhais, N. and Wutzler, T. and Schepaschenko, D. and Shvidenko, A. and Kompter, E. and Ahrens, B. and Levick, S.R. and Schmullius, C.},
  title = {Carbon stock and density of northern boreal and temperate forests},
  journal = {Global Ecology and Biogeography},
  year = {2014},
  volume = {23},
  number = {3},
  pages = {297-310},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893876661&doi=10.1111%2fgeb.12125&partnerID=40&md5=25cc945d9ba5faf63fc95bc69770a28a},
  doi = {10.1111/geb.12125}
}
Tosi L, Teatini P, Strozzi T and Da Lio C (2014), "Relative land subsidence of the venice coastland, Italy", Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes. , pp. 171-173. Springer International Publishing.
Abstract: The Venice coastland, Italy, is an emblematic case of a coastal area prone to progressive submersion by the rising of the sea. Although the city of Venice represents the most relevant case in the northern Adriatic coast, the loss in ground elevation with respect to the sea level, i.e. the relative land subsidence (RLS), is particularly important not only in sectors directly affected by the marine ingression but also in the in-land coastal plain. In this work we quantify the RLS occurred over the period 1992-2010 in the Venice coastland by the superimposition of the Adriatic sea level rise to the ground displacements assessed by the Interferometric Point Target Analysis performed on ERS-1/2 and ENVISAT scenes. Results show that the lowering of certain portions of the coastland relative to the mean sea level amounts to several centimeters, which are values particularly severe for the maintenance and management of the coastal area. Springer International Publishing Switzerland 2014.
BibTeX:
@book{Tosi2014171,
  author = {Tosi, L. and Teatini, P. and Strozzi, T. and Da Lio, C.},
  title = {Relative land subsidence of the venice coastland, Italy},
  journal = {Engineering Geology for Society and Territory - Volume 4: Marine and Coastal Processes},
  publisher = {Springer International Publishing},
  year = {2014},
  pages = {171-173},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948082873&doi=10.1007%2f978-3-319-08660-6_32&partnerID=40&md5=3bb869be870efef162660e044eb6479b},
  doi = {10.1007/978-3-319-08660-6_32}
}
Walter T, Shirzaei M, Manconi A, Solaro G, Pepe A, Manzo M and Sansosti E (2014), "Possible coupling of Campi Flegrei and Vesuvius as revealed by InSAR time series, correlation analysis and time dependent modeling", Journal of Volcanology and Geothermal Research. Vol. 280, pp. 104-110. Elsevier.
Abstract: Volcanoes are often considered as isolated systems, however, evidences increase that adjacent volcanoes are directly coupled or may be closely related to remote triggers. At the Italian volcanoes Campi Flegrei and Vesuvius, as well as adjacent volcano-tectonic systems, all located in the Campania Volcanic Province with  . 2. million inhabitants, a new analysis of satellite radar data reveals allied deformation activity. Here we show that during the 16-year records from 1992 to 2008, identified episodes of deformation have occurred in correlation. Albeit differences in the quantity of deformation, the sign, frequency and rate of pressure changes at reservoirs beneath Campi Flegrei and Vesuvius can be very similar, allowing to infer that pressure changes originating from a magmatic or tectonic source external to the shallow volcano magma plumbing systems is a likely cause. Such a fluid-mechanical coupling sheds light on the earlier episodes of correlated eruptions and deformations occurring during the historical roman times. 2014 Elsevier B.V.
BibTeX:
@article{Walter2014104,
  author = {Walter, T.R. and Shirzaei, M. and Manconi, A. and Solaro, G. and Pepe, A. and Manzo, M. and Sansosti, E.},
  title = {Possible coupling of Campi Flegrei and Vesuvius as revealed by InSAR time series, correlation analysis and time dependent modeling},
  journal = {Journal of Volcanology and Geothermal Research},
  publisher = {Elsevier},
  year = {2014},
  volume = {280},
  pages = {104-110},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901585335&doi=10.1016%2fj.jvolgeores.2014.05.006&partnerID=40&md5=cc728517911345d4e5af73131e0472d5},
  doi = {10.1016/j.jvolgeores.2014.05.006}
}
Wiesmann A, Caduff R, Strozzi T, Papke J and Matzler C (2014), "Monitoring of dynamic changes in alpine snow with terrestrial radar imagery", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3662-3665. Institute of Electrical and Electronics Engineers Inc..
Abstract: Remote sensing of snow with active and passive microwaves on terrestrial, aircraft and satellite platforms has a long tradition. However, the observation of dynamic processes on alpine slopes is difficult to achieve by fixed orbits and flight schedules. Terrestrial radar interferometers allow to overcome some of these constraints due to the portability of the system, the possibility to make repeat acquisitions in minute intervals, and the local observation capability. Results in the Swiss Alps prove the potential of the methodology to measure rapid and local changes in snow parameters such as changes of the liquid water content, sudden mechanical impact on the snowpack due to skiers and avalanches. Using standard interferometric techniques a local snow displacement map was computed providing information about the spatial and temporal behavior of creeping snow. 2014 IEEE.
BibTeX:
@conference{Wiesmann20143662,
  author = {Wiesmann, A. and Caduff, R. and Strozzi, T. and Papke, J. and Matzler, C.},
  title = {Monitoring of dynamic changes in alpine snow with terrestrial radar imagery},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2014},
  pages = {3662-3665},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911417045&doi=10.1109%2fIGARSS.2014.6947277&partnerID=40&md5=b072a7323e31d94eeed1dd67711bc64f},
  doi = {10.1109/IGARSS.2014.6947277}
}
Allasia P, Manconi A, Giordan D, Baldo M and Lollino G (2013), "ADVICE: A new approach for near-real-time monitoring of surface displacements in landslide hazard scenarios", Sensors (Switzerland). Vol. 13(7), pp. 8285-8302. MDPI AG.
Abstract: We present a new method for near-real-time monitoring of surface displacements due to landslide phenomena, namely ADVanced dIsplaCement monitoring system for Early warning (ADVICE). The procedure includes: (i) data acquisition and transfer protocols; (ii) data collection, filtering, and validation; (iii) data analysis and restitution through a set of dedicated software; (iv) recognition of displacement/velocity threshold, early warning messages via SMS and/or emails; (v) automatic publication of the results on a dedicated webpage. We show how the system evolved and the results obtained by applying ADVICE over three years into a real early warning scenario relevant to a large earthflow located in southern Italy. ADVICE has speed-up and facilitated the understanding of the landslide phenomenon, the communication of the monitoring results to the partners, and consequently the decision-making process in a critical scenario. Our work might have potential applications not only for landslide monitoring but also in other contexts, as monitoring of other geohazards and of complex infrastructures, as open-pit mines, buildings, dams, etc. 2013 by the authors; licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Allasia20138285,
  author = {Allasia, P. and Manconi, A. and Giordan, D. and Baldo, M. and Lollino, G.},
  title = {ADVICE: A new approach for near-real-time monitoring of surface displacements in landslide hazard scenarios},
  journal = {Sensors (Switzerland)},
  publisher = {MDPI AG},
  year = {2013},
  volume = {13},
  number = {7},
  pages = {8285-8302},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879514742&doi=10.3390%2fs130708285&partnerID=40&md5=ecd3b7fb002a5035115bee5a879b7382},
  doi = {10.3390/s130708285}
}
Askne J, Fransson J, Santoro M, Soja M and Ulander L (2013), "Model-based biomass estimation of a hemi-boreal forest from multitemporal tanDEM-X acquisitions", Remote Sensing. Vol. 5(11), pp. 5574-5597. MDPI AG.
Abstract: Above-ground forest biomass is a significant variable in the terrestrial carbon budget, but is still estimated with relatively large uncertainty. Remote sensing methods can improve the characterization of the spatial distribution and estimation accuracy of biomass; in this respect, it is important to examine the potential offered by new sensors. To assess the contribution of the TanDEM-X mission, eighteen interferometric Synthetic Aperture Radar (SAR) image pairs acquired over the hemi-boreal test site of Remningstorp in Sweden were investigated. Three models were used for interpretation of TanDEM-X signatures and above-ground biomass retrieval: Interferometric Water Cloud Model (IWCM), Random Volume over Ground (RVoG) model, and a simple model based on penetration depth (PD). All use an allometric expression to relate above-ground biomass to forest height measured by TanDEM-X. The retrieval was assessed on 201 forest stands with a minimum size of 1 ha, and ranging from 6 to 267 Mg/ha (mean biomass of 105 Mg/ha) equally divided into a model training dataset and a validation test dataset. Biomass retrieved using the IWCM resulted in a Root Mean Square Error (RMSE) between 17% and 33%, depending on acquisition date and image acquisition geometry (angle of incidence, interferometric baseline, and orbit type). The RMSE in the case of the RVoG and the PD models were slightly higher. A multitemporal estimate of the above-ground biomass using all eighteen acquisitions resulted in an RMSE of 16% with R2 = 0.93. These results prove the capability of TanDEM-X interferometric data to estimate forest aboveground biomass in the boreal zone.. 2013 by the authors.
BibTeX:
@article{Askne20135574,
  author = {Askne, J.I.H. and Fransson, J.E.S. and Santoro, M. and Soja, M.J. and Ulander, L.M.H.},
  title = {Model-based biomass estimation of a hemi-boreal forest from multitemporal tanDEM-X acquisitions},
  journal = {Remote Sensing},
  publisher = {MDPI AG},
  year = {2013},
  volume = {5},
  number = {11},
  pages = {5574-5597},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904625067&doi=10.3390%2frs5115574&partnerID=40&md5=42bf62db4f8e472dee46cd96c8626d9f},
  doi = {10.3390/rs5115574}
}
Burjack I, Santoro M and Schmullius C (2013), "Change analysis of sar based growing stock volume maps in northeast China for 2005 - 2010", In European Space Agency, (Special Publication) ESA SP. Vol. 704 SP
BibTeX:
@conference{Burjack2013,
  author = {Burjack, I. and Santoro, M. and Schmullius, C.},
  title = {Change analysis of sar based growing stock volume maps in northeast China for 2005 - 2010},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  year = {2013},
  volume = {704 SP},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892684220&partnerID=40&md5=136c8e1604876e29fb07b46bfcc218bb}
}
Caduff R, Strozzi T and Wiesmann A (2013), "Successful application of terrestrial radar interferometry for the extensive measurement of extraordinary landslide movements in the area of Hintergraben (Obwalden) [Erfolgreicher Einsatz terrestrischer Radar-Interferometrie zur flachenhaften Vermessung von ausserordentlichen Hangrutschungsbewegungen im Gebiet Hintergraben (OW)]", Bulletin fuer Angewandte Geologie. Vol. 18(2), pp. 129-138. Ver. Schweizerischer Petroleum Geol. und Ing..
Abstract: Terrestrial radar interferometry allows precise detection and measurement of surface deformation related to mass movements. One of the known limitations of this technology is temporal decorrelation, affecting in particular its application in heavily vegetated areas. Based on the exceptional landslide activity in the area of Hintergraben (OWl in the Swiss Alpine Foreland we show in this study that an almost complete coverage of surface deformation can be achieved even over dense grassland with short acquisition time intervals of 3 minutes and selective post-processing. Two measurement campaigns performed on May 5 and 28, 2013 demonstrate the successful application of terrestrial radar interferometry for the measurement of surface displacement in the case of low grass-heigths (max. 20 cm) respectively grass-heights reaching 1 m. We show that surface deformation rates decreased from max. h0 cm/day to max. 10 cm/day in the 3 weeks period. The findings are in good agreement with punctual control measurements performed with tachymetry.
BibTeX:
@article{Caduff2013129,
  author = {Caduff, R. and Strozzi, T. and Wiesmann, A.},
  title = {Successful application of terrestrial radar interferometry for the extensive measurement of extraordinary landslide movements in the area of Hintergraben (Obwalden) [Erfolgreicher Einsatz terrestrischer Radar-Interferometrie zur flachenhaften Vermessung von ausserordentlichen Hangrutschungsbewegungen im Gebiet Hintergraben (OW)]},
  journal = {Bulletin fuer Angewandte Geologie},
  publisher = {Ver. Schweizerischer Petroleum Geol. und Ing.},
  year = {2013},
  volume = {18},
  number = {2},
  pages = {129-138},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006643546&doi=10.5169%2fseals-391152&partnerID=40&md5=de16dc72f30a9b370fe3bee067fe2a38},
  doi = {10.5169/seals-391152}
}
De Michele M, Raucoules D, Wegmüller U and Bignami C (2013), "Synthetic aperture radar (sar) doppler anomaly detected during the 2010 merapi (Java, Indonesia) eruption", IEEE Geoscience and Remote Sensing Letters. Vol. 10(6), pp. 1319-1323.
Abstract: In this letter, we report the presence of a localized Doppler anomaly occurring during the focusing of a Radarsat-2 data set acquired on the Merapi volcano (Indonesia) during the devastating 2010 eruption. The Doppler anomaly is manifested as 3-km-wide bull's-eye-shaped azimuth pixel shifts between two subaperture images. The Doppler anomaly is centered on the summit-south flank of the Merapi volcano. The pixel shifts reach up to 11.6 m. Since the Merapi volcano was undergoing a large eruption during the data acquisition, it is possible that there is a volcano-related phenomenon that has delayed the radar signal so much to create measurable pixel offsets within a single synthetic aperture radar (SAR) data set, similar, but more extensive, to the signal generated by targets motions; similar, but less extensive, to the signal generated by ionospheric perturbations. It is known that the SAR signal is delayed as it passes through heterogeneous layers of the atmosphere, but this delay typically affects the SAR signal to a fraction of the phase cycle or few centimeters depending on the radar wavelength employed by the system. We investigate the source of this anomalous metric signal; we review the theoretical basis of SAR image focusing, and we try to provide a consistent physical framework to our observations. Our results are compatible with the SAR signal being perturbed during the actual process of image focusing by the presence of a contrasting medium located approximately between 6-and 12.5-km altitude, which we propose being associated with the presence of volcanic ash plume. 2013 IEEE.
BibTeX:
@article{DeMichele20131319,
  author = {De Michele, M. and Raucoules, D. and Wegmüller, U. and Bignami, C.},
  title = {Synthetic aperture radar (sar) doppler anomaly detected during the 2010 merapi (Java, Indonesia) eruption},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  year = {2013},
  volume = {10},
  number = {6},
  pages = {1319-1323},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886584504&doi=10.1109%2fLGRS.2013.2239602&partnerID=40&md5=76f4cfd6a89aad8dc7c6e9b1db4ea270},
  doi = {10.1109/LGRS.2013.2239602}
}
Del Ventisette C, Ciampalini A, Manunta M, Calò F, Paglia L, Ardizzone F, Mondini A, Reichenbach P, Mateos R, Bianchini S, Garcia I, Fusi B, Deák Z, Rádi K, Graniczny M, Kowalski Z, Piatkowska A, Przylucka M, Retzo T, Strozzi T, Colombo D, Mora O, Sánchez F, Herrera G, Moretti S, Casagli N and Guzzetti F (2013), "Exploitation of large archives of ERS and ENVISAT C-band SAR data to characterize ground deformations", Remote Sensing. Vol. 5(8), pp. 3896-3917.
Abstract: In the last few years, several advances have been made in the use of radar images to detect, map and monitor ground deformations. DInSAR (Differential Synthetic Aperture Radar Interferometry) and A-DInSAR/PSI (Advanced DInSAR/Persistent Scatterers Interferometry) technologies have been successfully applied in the study of deformation phenomena induced by, for example, active tectonics, volcanic activity, ground water exploitation, mining, and landslides, both at local and regional scales. In this paper, the existing European Space Agency (ESA) archives (acquired as part of the FP7-DORIS project), which were collected by the ERS-1/2 and ENVISAT satellites operating in the microwave C-band, were analyzed and exploited to understand the dynamics of landslide and subsidence phenomena. In particular, this paper presents the results obtained as part of the FP7-DORIS project to demonstrate that the full exploitation of very long deformation time series (more than 15 years) can play a key role in understanding the dynamics of natural and human-induced hazards. 2013 by the authors.
BibTeX:
@article{DelVentisette20133896,
  author = {Del Ventisette, C. and Ciampalini, A. and Manunta, M. and Calò, F. and Paglia, L. and Ardizzone, F. and Mondini, A.C. and Reichenbach, P. and Mateos, R.M. and Bianchini, S. and Garcia, I. and Fusi, B. and Deák, Z.V. and Rádi, K. and Graniczny, M. and Kowalski, Z. and Piatkowska, A. and Przylucka, M. and Retzo, T. and Strozzi, T. and Colombo, D. and Mora, O. and Sánchez, F. and Herrera, G. and Moretti, S. and Casagli, N. and Guzzetti, F.},
  title = {Exploitation of large archives of ERS and ENVISAT C-band SAR data to characterize ground deformations},
  journal = {Remote Sensing},
  year = {2013},
  volume = {5},
  number = {8},
  pages = {3896-3917},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884691971&doi=10.3390%2frs5083896&partnerID=40&md5=a56fc85096ace5a9d5ad5572d5cf5d88},
  doi = {10.3390/rs5083896}
}
Frey O, Hajnsek I and Wegmüller U (2013), "Spaceborne SAR tomography in urban areas", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 69-72.
Abstract: Persistent scatterer interferometry relies on the assumption that only one dominant scatterer is present per range-azimuth resolution cell. If this criterion is not met the point target candidate is discarded during the iterative processing sequence. This one-scatterer assumption contrasts with the fact that in urban scenarios layover is an ubiquitous phenomenon, and, therefore two or even more scatterers per resolution cell occur frequently. SAR tomography has the potential to support persistent scatterer interferometry in urban areas by providing a means to identify and separate two scatterers in elevation direction. In this paper, we explore an interferometric stack consisting of 25 ENVISAT/ASAR SLC images over Bucharest using SAR tomography approaches combined with interferometric point target processing. Elevation profiles are extracted using beamforming and truncated singular value decomposition focusing approaches. 2013 IEEE.
BibTeX:
@conference{Frey201369,
  author = {Frey, O. and Hajnsek, I. and Wegmüller, U.},
  title = {Spaceborne SAR tomography in urban areas},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2013},
  pages = {69-72},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894263807&doi=10.1109%2fIGARSS.2013.6721094&partnerID=40&md5=67c9276491f73b730ca2c0ba1781a949},
  doi = {10.1109/IGARSS.2013.6721094}
}
Frey O, Santoro M, Werner C and Wegmüller U (2013), "DEM-based SAR pixel-area estimation for enhanced geocoding refinement and radiometric Normalization", IEEE Geoscience and Remote Sensing Letters. Vol. 10(1), pp. 48-52.
Abstract: Precise terrain-corrected georeferencing of synthetic aperture radar (SAR) images and derived products in range-Doppler coordinates is important with respect to several aspects, such as data interpretation, combination with other geodata products, and transformation of, e.g., terrain heights into SAR geometry as used in differential interferometric SAR (DInSAR) applications. For georeferencing, a lookup table is calculated and then refined based on a coregistration of the actual SAR image to a simulated SAR image. The impact of using two different implementations of such a simulator of topography-induced radar brightness, 1) an approach based on angular relationships and 2) a pixel-area-based method, is discussed in this letter. It is found that the pixel-area-based method leads to considerable improvements with regard to the robustness of georeferencing and also with regard to radiometric normalization in layover-affected areas. 2012 IEEE.
BibTeX:
@article{Frey201348,
  author = {Frey, O. and Santoro, M. and Werner, C.L. and Wegmüller, U.},
  title = {DEM-based SAR pixel-area estimation for enhanced geocoding refinement and radiometric Normalization},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  year = {2013},
  volume = {10},
  number = {1},
  pages = {48-52},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887623092&doi=10.1109%2fLGRS.2012.2192093&partnerID=40&md5=1bbc732193929b74d40883764ef29f49},
  doi = {10.1109/LGRS.2012.2192093}
}
Frey O, Werner C, Wegmüller U, Wiesmann A, Henke D and Magnard C (2013), "A car-borne SAR and InSAR experiment", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 93-96.
Abstract: In this contribution, a car-borne SAR and InSAR experiment is described. The slope of a valley was imaged by means of a single-pass InSAR system mounted on a car driving on roads along the bottom of the valley. The GAMMA portable radar interferometer GPRI-II hardware with a modified antenna configuration was used for data acquisition. The experimental setup (1), SAR imagery focused along a slightly curved sensor trajectory (2), and first interferometric results (3) obtained using this configuration are presented. 2013 IEEE.
BibTeX:
@conference{Frey201393,
  author = {Frey, O. and Werner, C.L. and Wegmüller, U. and Wiesmann, A. and Henke, D. and Magnard, C.},
  title = {A car-borne SAR and InSAR experiment},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2013},
  pages = {93-96},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894263754&doi=10.1109%2fIGARSS.2013.6721100&partnerID=40&md5=c0f5a8b6f0977966535c84ae15372a62},
  doi = {10.1109/IGARSS.2013.6721100}
}
Garcia-Davalillo J-C, Herrera G, Notti D, Hernandez-Ruiz M, Fernandez-Merodo J-A, Alvarez-Fernandez I, Gonzalez-Nicieza C, Strozzi T and Mora O (2013), "InSAR data for mapping and monitoring landslides in Tena valley", In Landslide Science and Practice: Early Warning, Instrumentation and Monitoring. Vol. 2, pp. 243-249.
Abstract: In the last 20 years the exploitation of satellite SAR interferometry has shown a considerable improvement due to the development of new InSAR PSI techniques and the availability of the new satellite sensors with higher spatial and temporal resolution. One of the most interesting applications is the possibility of mapping slow landslides processes. In this paper we present an analysis of the advantages and disadvantages of using L-, C- and Xband sensors for mapping and monitoring landslides in the Rio Gállego upper basin (Central Pyrenees, Spain) techniques. Springer-Verlag Berlin Heidelberg 2013.
BibTeX:
@conference{GarciaDavalillo2013243,
  author = {Garcia-Davalillo, J.-C. and Herrera, G. and Notti, D. and Hernandez-Ruiz, M. and Fernandez-Merodo, J.-A. and Alvarez-Fernandez, I. and Gonzalez-Nicieza, C. and Strozzi, T. and Mora, O.},
  title = {InSAR data for mapping and monitoring landslides in Tena valley},
  booktitle = {Landslide Science and Practice: Early Warning, Instrumentation and Monitoring},
  year = {2013},
  volume = {2},
  pages = {243-249},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898060853&doi=10.1007%2f978-3-642-31445-2-31&partnerID=40&md5=4792fc91c99eb2b8cff2f6e66fb5efeb},
  doi = {10.1007/978-3-642-31445-2-31}
}
Giordan D, Allasia P, Manconi A, Baldo M, Santangelo M, Cardinali M, Corazza A, Albanese V, Lollino G and Guzzetti F (2013), "Morphological and kinematic evolution of a large earthflow: The Montaguto landslide, southern Italy", Geomorphology. Vol. 187, pp. 61-79.
Abstract: We studied the geomorphological evolution of the Montaguto landslide, a 3.1×103m long earthflow in the southern Apennines of Italy. Following an analysis of the different methods and techniques available to measure surface modifications caused by a large earthflow, we selected a combination of monitoring techniques compatible with the Montaguto case study. We exploited: (i) visual interpretation of aerial and satellite imagery, (ii) quantitative analysis of six digital elevation models (DEMs) covering the landslide area, and (iii) a large set of high-accuracy three-dimensional topographic measurements captured by three robotised total stations (RTSs). Integration of the results obtained from the different monitoring techniques allowed us to investigate the long (multi-decadal) and short (seasonal) term evolution of the Montaguto earthflow in the 58-year period (1954-2011). The examination of the available aerial, satellite and hill-shade images revealed a cyclic, long-term behaviour of mass movements of different types in the Rio Nocelle catchment occupied by the recent Montaguto earthflow. The combined analysis of the six DEMs allowed measuring the material eroded from the landslide crown area (V 1.4×106m3) and deposited in the landslide toe area (V 1.2×106m3) in the period from 2005 to June 2011. The analysis of a large set of high-accuracy topographic measurements revealed the kinematical characteristics of different sectors of the active earthflow, and allowed the reconstruction of the temporal and spatial evolution of the moving failure. The insights obtained are significant for the geo-mechanical modelling of similar earthflows, regional landslide mapping, and the evaluation of hazard and risk posed by large earthflows in southern Italy or similar physiographic regions. 2013 Elsevier B.V.
BibTeX:
@article{Giordan201361,
  author = {Giordan, D. and Allasia, P. and Manconi, A. and Baldo, M. and Santangelo, M. and Cardinali, M. and Corazza, A. and Albanese, V. and Lollino, G. and Guzzetti, F.},
  title = {Morphological and kinematic evolution of a large earthflow: The Montaguto landslide, southern Italy},
  journal = {Geomorphology},
  year = {2013},
  volume = {187},
  pages = {61-79},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875485076&doi=10.1016%2fj.geomorph.2012.12.035&partnerID=40&md5=17fc3c027cdd4f474815dffb1be2728e},
  doi = {10.1016/j.geomorph.2012.12.035}
}
Grenerczy G and Wegmüller U (2013), "Deformation analysis of a burst red mud reservoir using combined descending and ascending pass ENVISAT ASAR data", Natural Hazards. Vol. 65(3), pp. 2205-2214.
Abstract: After the catastrophic failure of a red mud reservoir in Hungary, we performed a persistent scatterer radar interferometry (PSI) deformation analysis to investigate the stability and motion history of the entire area focusing on the dam walls of the collapsed structure. Our aim was to contribute to the better understanding of the disaster and, more importantly, to see whether it was possible to prognosticate and consequently prevent the failure of the reservoir and to help avoiding such occurrences worldwide. Our earlier data revealed that the surroundings were generally very stable over the investigated 8 years time interval, whereas significant continuous motions were detected on the embankments. After these first results, we continued our PSI deformation study with the processing and evaluation of the complete ascending pass ENVISAT dataset and later with the combination of the results of the two different observation geometries. From our descending and ascending data, it was possible to combine motions determined in line-of-sight directions and to investigate horizontal and vertical components allowing the estimation of 'total' velocity vectors, magnitude and directions, at those locations of the reservoir and on the entire study area where reflections from both projections were available. It was also possible to get information from several other segments of the embankments of the failed reservoir where the descending geometry was unfavorable. With the combination, the complete ENVISAT PSI analysis using both ascending and descending orbit data enabled us to constrain the role of the soil structure and to look at the differential uplift or subsidence due to swelling soil effect. It also enabled us to constrain the role of the deposited mud, slurry, and accumulated water, and the strength and design of the structure in the failure of the red mud reservoir. Models were also constructed to visualize the observed motions of the reservoir embankments and to highlight the location of strain and stress accumulation providing significant constraints on the natural and anthropogenic origin of the disaster. 2012 Springer Science+Business Media Dordrecht.
BibTeX:
@article{Grenerczy20132205,
  author = {Grenerczy, G. and Wegmüller, U.},
  title = {Deformation analysis of a burst red mud reservoir using combined descending and ascending pass ENVISAT ASAR data},
  journal = {Natural Hazards},
  year = {2013},
  volume = {65},
  number = {3},
  pages = {2205-2214},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871937028&doi=10.1007%2fs11069-012-0470-4&partnerID=40&md5=3fed848673da437d7d8bc8d11dba8be4},
  doi = {10.1007/s11069-012-0470-4}
}
Jakobsen P, Wegmüller U, Capes R and Pedersen S (2013), "Terrain subsidence detected by satellite radar scanning of the Copenhagen area, Denmark, and its relation to the tectonic framework", Geological Survey of Denmark and Greenland Bulletin. (28), pp. 25-28.
BibTeX:
@article{Jakobsen201325,
  author = {Jakobsen, P.R. and Wegmüller, U. and Capes, R. and Pedersen, S.A.S.},
  title = {Terrain subsidence detected by satellite radar scanning of the Copenhagen area, Denmark, and its relation to the tectonic framework},
  journal = {Geological Survey of Denmark and Greenland Bulletin},
  year = {2013},
  number = {28},
  pages = {25-28},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879516566&partnerID=40&md5=6c131f18eda5769902307f98fb7b6204}
}
Jones B, Gusmeroli A, Arp C, Strozzi T, Grosse G, Gaglioti B and Whitman M (2013), "Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data", International Journal of Remote Sensing. Vol. 34(23), pp. 8267-8279. Taylor and Francis Ltd..
Abstract: Arctic freshwater ecosystems have responded rapidly to climatic changes over the last half century. Lakes and rivers are experiencing a thinning of the seasonal ice cover, which may increase potential over-wintering freshwater habitat, winter water supply for industrial withdrawal, and permafrost degradation. Here, we combined the use of ground penetrating radar (GPR) and high-resolution (HR) spotlight TerraSAR-X (TSX) satellite data (1.25 m resolution) to identify and characterize floating ice and grounded ice conditions in lakes, ponds, beaded stream pools, and an alluvial river channel. Classified ice conditions from the GPR and the TSX data showed excellent agreement: 90.6% for a predominantly floating ice lake, 99.7% for a grounded ice lake, 79.0% for a beaded stream course, and 92.1% for the alluvial river channel. A GIS-based analysis of 890 surface water features larger than 0.01 ha showed that 42% of the total surface water area potentially provided over-wintering habitat during the 2012/2013 winter. Lakes accounted for 89% of this area, whereas the alluvial river channel accounted for 10% and ponds and beaded stream pools each accounted for <1%. Identification of smaller landscape features such as beaded stream pools may be important because of their distribution and role in connecting other water bodies on the landscape. These findings advance techniques for detecting and knowledge associated with potential winter habitat distribution for fish and invertebrates at the local scale in a region of the Arctic with increasing stressors related to climate and land use change. 2013 This work was authored as part of the Contributors' official duties as Employees of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under US Law.
BibTeX:
@article{Jones20138267,
  author = {Jones, B.M. and Gusmeroli, A. and Arp, C.D. and Strozzi, T. and Grosse, G. and Gaglioti, B.V. and Whitman, M.S.},
  title = {Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data},
  journal = {International Journal of Remote Sensing},
  publisher = {Taylor and Francis Ltd.},
  year = {2013},
  volume = {34},
  number = {23},
  pages = {8267-8279},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886933697&doi=10.1080%2f2150704X.2013.834392&partnerID=40&md5=1995712d0acfeced62fe2ce085b76a5e},
  doi = {10.1080/2150704X.2013.834392}
}
Koffi E, Graham E and Matzler C (2013), "The water vapour flux above Switzerland and its role in the August 2005 extreme precipitation and flooding", Meteorologische Zeitschrift. Vol. 22(3), pp. 329-342.
Abstract: The water budget approach is applied to an atmospheric box above Switzerland (hereafter referred to as the "Swiss box") to quantify the atmospheric water vapour flux using ECMWF ERA-Interim reanalyses. The results confirm that the water vapour flux through the Swiss box is highly temporally variable, ranging from 1 to 5 × 107 kg/s during settled anticyclonic weather, but increasing in size by a factor of ten or more during high speed currents of water vapour. Overall, Switzerland and the Swiss box "import" more water vapour than it "exports", but the amount gained remains only a small fraction (1% to 5%) of the total available water vapour passing by. High inward water vapour fluxes are not necessarily linked to high precipitation episodes. The water vapour flux during the August 2005 floods, which caused severe damage in central Switzerland, is examined and an assessment is made of the computed water vapour fluxes compared to high spatio-temporal rain gauge and radar observations. About 25% of the incoming water vapour flux was stored in Switzerland. The computed water vapour fluxes from ECMWF data compare well with the mean rain gauge observations and the combined rain-gauge radar precipitation products. by Gebruder Borntraeger 2013.
BibTeX:
@article{Koffi2013329,
  author = {Koffi, E.N. and Graham, E. and Matzler, C.},
  title = {The water vapour flux above Switzerland and its role in the August 2005 extreme precipitation and flooding},
  journal = {Meteorologische Zeitschrift},
  year = {2013},
  volume = {22},
  number = {3},
  pages = {329-342},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887830024&doi=10.1127%2f0941-2948%2f2013%2f0392&partnerID=40&md5=ffcb1febf24d1c8799c3a5f89d20bf48},
  doi = {10.1127/0941-2948/2013/0392}
}
Kos A, Strozzi T, Stockmann R, Wiesmann A and Werner C (2013), "Detection and characterization of rock slope instabilities using a portable radar interferometer (GPRI)", In Landslide Science and Practice: Early Warning, Instrumentation and Monitoring. Vol. 2, pp. 325-329.
Abstract: A portable radar interferomter was used to periodically monitor a rock wall, where millimeter-scale displacements (0.5-0.6 mm/month) on an unstable rock slab were detected. Preliminary interpretation of a radar images acquired over a 5 month period revealed evidence for combined toppling and buckling failure mechanisms on the rock slab. The rock wall of interest has a history of block fall activity, which directly endangers a roadway in Canton Graubunden, Switzerland. Springer-Verlag Berlin Heidelberg 2013.
BibTeX:
@conference{Kos2013325,
  author = {Kos, A. and Strozzi, T. and Stockmann, R. and Wiesmann, A. and Werner, C.},
  title = {Detection and characterization of rock slope instabilities using a portable radar interferometer (GPRI)},
  booktitle = {Landslide Science and Practice: Early Warning, Instrumentation and Monitoring},
  year = {2013},
  volume = {2},
  pages = {325-329},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898073440&doi=10.1007%2f978-3-642-31445-2-42&partnerID=40&md5=dc39036747654a651913971b31c5aa9a},
  doi = {10.1007/978-3-642-31445-2-42}
}
Ling F, Li Z, Chen E, Huang Y, Tian X, Schmullius C, Leiterer R, Reiche J and Santoro M (2013), "Forest and non-forest mapping with envisat asar images", In European Space Agency, (Special Publication) ESA SP. Vol. 704 SP
Abstract: Envisat Advanced Synthetic Aperture Radar (ASAR) dual-polarization data are shown to be effective for regional forest monitoring. To this scope, an automatic SAR image preprocessing procedure was developed using SRTM DEM and Landsat TM image for geocoding in rugged terrain and smooth terrain areas, respectively. An object-oriented forest and non-forest classification method is then proposed based on the HH to HV intensity ratio and HV images of ASAR data at single acquisition in winter. The developed methods were applied to forest and non-forest mapping in Northeast China. The overall accuracy, the user's accuracy and the producer's accuracy of forest are 83.7%, 85.6% and 75.7% respectively. The results indicate that the proposed methods are promising for operational forest mapping at regional scale.
BibTeX:
@conference{Ling2013a,
  author = {Ling, F. and Li, Z. and Chen, E. and Huang, Y. and Tian, X. and Schmullius, C. and Leiterer, R. and Reiche, J. and Santoro, M.},
  title = {Forest and non-forest mapping with envisat asar images},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  year = {2013},
  volume = {704 SP},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892720754&partnerID=40&md5=b9c3ffd31d228820cf9e8a1f4a1b5638}
}
Ling F, Li Z, Chen E, Huang Y, Tian X, Schmullius C, Leiterer R, Reiche J and Santoro M (2013), "Regional forest and non-forest mapping with envisat ASAR data", In European Space Agency, (Special Publication) ESA SP. Vol. 704 SP
BibTeX:
@conference{Ling2013b,
  author = {Ling, F. and Li, Z. and Chen, E. and Huang, Y. and Tian, X. and Schmullius, C. and Leiterer, R. and Reiche, J. and Santoro, M.},
  title = {Regional forest and non-forest mapping with envisat ASAR data},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  year = {2013},
  volume = {704 SP},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892682072&partnerID=40&md5=f5658d27f26e82e1df2a86ef5458818d}
}
Manconi A, Allasia P, Giordan D, Baldo M and Lollino G (2013), "Monitoring the stability of infrastructures in an emergency scenario: The "costa Concordia" vessel wreck", In Global View of Engineering Geology and the Environment - Proceedings of the International Symposium and 9th Asian Regional Conference of IAEG. , pp. 587-591.
Abstract: We present a summary of the monitoring activities performed by CNR-IRPI during the emergency scenario relevant to the "Costa Concordia" ship stranding, occurred on January 13, 2012, near the coast of Il Giglio island, Italy. Two Robotized Total Stations (RTS) were deployed in different times in order to monitor the stability of the vessel during the Search and Rescue activities, as well as the fuel recovery accomplishment. RTS data have been considered as an important support for the early warning system set up to ensure the safety of the operators. The dataset and results herein included are unique, and represent a peculiar and concrete opportunity to test the efficiency of specific monitoring techniques, which were developed to control and study phenomena relevant to engineering geology activities, also in very peculiar structural health's monitoring, relevant to an unforeseen emergency scenario. 2013 Taylor & Francis Group, London.
BibTeX:
@conference{Manconi2013587,
  author = {Manconi, A. and Allasia, P. and Giordan, D. and Baldo, M. and Lollino, G.},
  title = {Monitoring the stability of infrastructures in an emergency scenario: The "costa Concordia" vessel wreck},
  booktitle = {Global View of Engineering Geology and the Environment - Proceedings of the International Symposium and 9th Asian Regional Conference of IAEG},
  year = {2013},
  pages = {587-591},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890074884&partnerID=40&md5=1ec570f3a76ab95620082d6e7adf3452}
}
Manconi A, Allasia P, Giordan D, Baldo M, Lollino G, Corazza A and Albanese V (2013), "Landslide 3D surface deformation model obtained via RTS measurements", In Landslide Science and Practice: Early Warning, Instrumentation and Monitoring. Vol. 2, pp. 431-436.
Abstract: We present a new procedure that allows retrieving in near-real-time 3D surface deformation models starting from data acquired via Robotized Total Stations (RTS). The RTS measurements are first pre-processed and then implemented on 3D maps that include vector arrows representative of the intensities and of the real directions of motion in a given system of coordinates. The 3D surface deformation models are finally overlain on a DTM and/or on an updated picture of the monitored area. We discuss an example of application to an active large-scale landslide located in the area of Montaguto (southern Italy, ca. 100 km northeast from Naples). In this complex landslide scenario, the use of 3D representations of the surface deformation simplified the understanding of the evolution of the landslide phenomenon and received positive feedbacks from operators of the Italian Civil Protection Department. Springer-Verlag Berlin Heidelberg 2013.
BibTeX:
@conference{Manconi2013431,
  author = {Manconi, A. and Allasia, P. and Giordan, D. and Baldo, M. and Lollino, G. and Corazza, A. and Albanese, V.},
  title = {Landslide 3D surface deformation model obtained via RTS measurements},
  booktitle = {Landslide Science and Practice: Early Warning, Instrumentation and Monitoring},
  year = {2013},
  volume = {2},
  pages = {431-436},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898070531&doi=10.1007%2f978-3-642-31445-2-56&partnerID=40&md5=5aa3c1b94a1f63d599e2f1bf920fd6a9},
  doi = {10.1007/978-3-642-31445-2-56}
}
Manunta M, Calo F, Ojha C, Ardizzone F, Guzzetti F, Mondini A, Reichenbach P, Bianchini S, Casagli N, Ciampalini A, Del Ventisette C, Moretti S, Garcia I, Herrera G, Mateos R, Fusi B, Graniczny M, Kowalski Z, Piatkowska A, Surala M, Retzo H, Strozzi T, Colombo D, Mora O and Sanchez C (2013), "The European DORIS downstream service as a multi-scale system for landslides and subsidence risk management", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 33-36.
Abstract: We focused on the joint exploitation of satellite and ground-based technologies in order to understand the kinematic behavior of landslides and subsidence phenomena relevant to different test sites in Europe. In this context, we efficiently exploited C-band and X-band satellite and ground-based SAR data for the investigation of the temporal and spatial pattern of ground deformations caused by natural and human-induced hazards. The present work has been conducted within the FP7-EU DORIS project. 2013 IEEE.
BibTeX:
@conference{Manunta201333,
  author = {Manunta, M. and Calo, F. and Ojha, C. and Ardizzone, F. and Guzzetti, F. and Mondini, A.C. and Reichenbach, P. and Bianchini, S. and Casagli, N. and Ciampalini, A. and Del Ventisette, C. and Moretti, S. and Garcia, I. and Herrera, G. and Mateos, R.M. and Fusi, B. and Graniczny, M. and Kowalski, Z. and Piatkowska, A. and Surala, M. and Retzo, H. and Strozzi, T. and Colombo, D. and Mora, O. and Sanchez, C.},
  title = {The European DORIS downstream service as a multi-scale system for landslides and subsidence risk management},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2013},
  pages = {33-36},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894288008&doi=10.1109%2fIGARSS.2013.6721085&partnerID=40&md5=206e8f0f3b4c89f71ccfcc7aa90e1054},
  doi = {10.1109/IGARSS.2013.6721085}
}
Santoro M, Cartus O, Fransson J, Shvidenko A, McCallum I, Hall R, Beaudoin A, Beer C and Schmullius C (2013), "Estimates of forest growing stock volume for sweden, central siberia, and québec using envisat advanced synthetic aperture radar backscatter data", Remote Sensing. Vol. 5(9), pp. 4503-4532.
Abstract: A study was undertaken to assess Envisat Advanced Synthetic Aperture Radar (ASAR) ScanSAR data for quantifying forest growing stock volume (GSV) across three boreal regions with varying forest types, composition, and structure (Sweden, Central Siberia, and Québec). Estimates of GSV were obtained using hyper-temporal observations of the radar backscatter acquired by Envisat ASAR with the BIOMASAR algorithm. In total, 5.3.106 km2 were mapped with a 0.01° pixel size to obtain estimates representative for the year of 2005. Comparing the SAR-based estimates to spatially explicit datasets of GSV, generated from forest field inventory and/or Earth Observation data, revealed similar spatial distributions of GSV. Nonetheless, the weak sensitivity of C-band backscatter to forest structural parameters introduced significant uncertainty to the estimated GSV at full resolution. Further discrepancies were observed in the case of different scales of the ASAR and the reference GSV and in areas of fragmented landscapes. Aggregation to 0.1° and 0.5° was then undertaken to generate coarse scale estimates of GSV. The agreement between ASAR and the reference GSV datasets improved; the relative difference at 0.5° was consistently within a magnitude of 20-30%. The results indicate an improvement of the characterization of forest GSV in the boreal zone with respect to currently available information. 2013 by the authors; licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Santoro20134503,
  author = {Santoro, M. and Cartus, O. and Fransson, J.E.S. and Shvidenko, A. and McCallum, I. and Hall, R.J. and Beaudoin, A. and Beer, C. and Schmullius, C.},
  title = {Estimates of forest growing stock volume for sweden, central siberia, and québec using envisat advanced synthetic aperture radar backscatter data},
  journal = {Remote Sensing},
  year = {2013},
  volume = {5},
  number = {9},
  pages = {4503-4532},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884676581&doi=10.3390%2frs5094503&partnerID=40&md5=fd5442b09f70efe874ce3b28cca3243c},
  doi = {10.3390/rs5094503}
}
Scherer D, Hall D, Hochschild V, Konig M, Winther J-G, Duguay C, Pivot F, Matzler C, Rau F, Seidel K, Solberg R and Walker A (2013), "Remote Sensing of Snow Cover", Remote Sensing in Northern Hydrology: Measuring Environmental Change. , pp. 7-38. American Geophysical Union.
Abstract: This chapter is dedicated to remote sensing of snow as one of the most important cryospheric components to be considered in Northern Hydrology. After a short introduction, general approaches in optical, thermal infrared, active and passive microwave, and airborne gamma remote sensing, including the most important systems, are presented and discussed. Then, specific applications of remote sensing of snow cover are shown, grouped by the respective snow properties, i.e., snow-covered area, liquid water content, snow water equivalent, snow reflectance, snow grain size, snow depth, and snow temperature. Finally, conclusions are drawn with respect to unresolved issues and future research needs. by the American Geophysical Union.
BibTeX:
@book{Scherer20137,
  author = {Scherer, D. and Hall, D.K. and Hochschild, V. and Konig, M. and Winther, J.-G. and Duguay, C.R. and Pivot, F. and Matzler, C. and Rau, F. and Seidel, K. and Solberg, R. and Walker, A.E.},
  title = {Remote Sensing of Snow Cover},
  journal = {Remote Sensing in Northern Hydrology: Measuring Environmental Change},
  publisher = {American Geophysical Union},
  year = {2013},
  pages = {7-38},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946839231&doi=10.1029%2f163GM03&partnerID=40&md5=51257c24c0624a567b5fec9cce6967b2},
  doi = {10.1029/163GM03}
}
Schlunegger F, Norton K and Caduff R (2013), "Hillslope Processes in Temperate Environments", Treatise on Geomorphology. Vol. 7, pp. 337-354. Elsevier Inc..
Abstract: In this chapter, we discuss the factors controlling the mechanisms and rates of hillslope failure in temperate environments with a major focus on the Swiss Alps. We frame this presentation by defining Alpine hillslopes as either strength- or transport-limited hillslopes. We organize this discussion into individual sections that outline how hillslope processes are related to (1) the mechanical strength and bedding orientation of bedrock, (2) the competition between channelized and hillslope processes, (3) hillslope-channel coupling relationships, and (4) fluvial erosion rates. We find that hillslope angles depend on bedrock strength along nonincised channels, but are not related to this parameter in inner gorges. We also find that valley flanks host deep-seated landslides where the bedrock dips parallel to the topographic slope. In the opposite case, the valley sides are dissected by a network of bedrock channels bordered by strength-limited hillslopes. In this chapter, we illustrate that a high ratio between sediment discharge on hillslopes and in channels explains the formation of smooth landscapes with low channel densities and long response times. This chapter considers the formation of strength-limited hillslopes as a consequence of an upslope-directed coupling between channels and hillslopes. The chapter also discusses that soil-mantled hillslopes occur where fluvial incision rates are less than weathering rates of bedrock, which are limited to 0.1-0.3mmyr-1. We finally present evidence for a decreasing trend of hillslope-derived sediment discharge during the Holocene, but predict an opposite trend in the nearest future as winters are warmer and wetter. 2013 Elsevier Inc. All rights reserved.
BibTeX:
@book{Schlunegger2013337,
  author = {Schlunegger, F. and Norton, K. and Caduff, R.},
  title = {Hillslope Processes in Temperate Environments},
  journal = {Treatise on Geomorphology},
  publisher = {Elsevier Inc.},
  year = {2013},
  volume = {7},
  pages = {337-354},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881089900&doi=10.1016%2fB978-0-12-374739-6.00183-4&partnerID=40&md5=f3ef34fe25cb9daf39321794313ac1c9},
  doi = {10.1016/B978-0-12-374739-6.00183-4}
}
Schmitt M, Magnard C, Stanko S, Ackermann C and Stilla U (2013), "Advanced high resolution SAR interferometry of urban areas with airborne millimetrewave radar", Photogrammetrie, Fernerkundung, Geoinformation. Vol. 2013(6), pp. 603-617.
Abstract: For rural and natural scenes, synthetic aperture radar interferometry (InSAR) has long been an operational technique for the generation of digital surface models. With the advent of sensors providing data in the decimetre resolution domain, also the analysis of densely built-up urban areas has become an increasingly important research topic. Due to the complexity of this kind of scenes, however, advanced interferometric techniques have to be employed. While usually satellite-borne stacks of multi-temporal data are collected in order to make use of differential SAR interferometry or the increasingly popular persistent scatterer technique, this article aims at the utilization of an airborne single-pass multi-baseline system working in the millimetrewave domain. Starting from the description of the exemplary German MEMPHIS sensor, the complete processing chain from the collection of necessary navigation data over the focusing of the raw SAR data to finally the application of sophisticated InSAR techniques is shown.
BibTeX:
@article{Schmitt2013603,
  author = {Schmitt, M. and Magnard, C. and Stanko, S. and Ackermann, C. and Stilla, U.},
  title = {Advanced high resolution SAR interferometry of urban areas with airborne millimetrewave radar},
  journal = {Photogrammetrie, Fernerkundung, Geoinformation},
  year = {2013},
  volume = {2013},
  number = {6},
  pages = {603-617},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84888409159&doi=10.1127%2f1432-8364%2f2013%2f0199&partnerID=40&md5=abd440f7c98a95b5189ce8bdd82a020e},
  doi = {10.1127/1432-8364/2013/0199}
}
Schmitt M, Maksymiuk O, Magnard C and Stilla U (2013), "Radargrammetric registration of airborne multi-aspect SAR data of urban areas", ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 86, pp. 11-20. Elsevier B.V..
Abstract: In this paper, the registration of decimeter-resolution airborne multi-aspect SAR (MASAR) data of inner city areas by application of the radargrammetric rager equations is investigated. The geometrical model is adapted to linear flight trajectories and zero-Doppler processed SAR data, whereas the observed trajectory parameters are adjusted using a strict Gauss-Helmert model and known ground control points. The significance of the estimated corrections is examined and the most suitable set of free parameters is determined. Finally, the methodology is applied to real test data of an airborne campaign over the city of Munich, Germany, and the feasability of the proposed radargrammetric registration method is shown. 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
BibTeX:
@article{Schmitt201311,
  author = {Schmitt, M. and Maksymiuk, O. and Magnard, C. and Stilla, U.},
  title = {Radargrammetric registration of airborne multi-aspect SAR data of urban areas},
  journal = {ISPRS Journal of Photogrammetry and Remote Sensing},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {86},
  pages = {11-20},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884810643&doi=10.1016%2fj.isprsjprs.2013.09.003&partnerID=40&md5=ae9e56f4e0205a675411cfe37b0800fe},
  doi = {10.1016/j.isprsjprs.2013.09.003}
}
Schmullius C, Leiterer R, Burjack I, Traut K, Santoro M, Li Z and Ling F (2013), "Forest dragon 2: Final results of the european partners", In European Space Agency, (Special Publication) ESA SP. Vol. 704 SP
Abstract: The European contribution to the Forest DRAGON 2 focused on the evaluation of multi-temporal, multisensor and multi-scale Earth Observation images and data products within the vegetation ecosystem of Northeast China. The forest growing stock volume (GSV) map produced with ERS-1/2 coherence images for 1995-1998 and two GSV maps produced from Envisat ASAR ScanSAR data for 2005 and 2010 were inter-compared with respect to several datasets (in situ, EO images and EO data products) to assess the plausibility of the GSV estimates, the contribution to land cover mapping and the dynamics over time. For this purpose, a multi-source database was set up including in situ data and EO data products. Land use / land cover (LULC) datasets identified mis-classification of GSV in the ERS dataset primarily for cropland. An a posteriori correction of the GSV resulted in an increase of overall accuracy up to 7%. LULC products can also support the fine tuning of the algorithm to estimate GSV from ASAR data particularly in transition regions between forest and shrubland. The ASAR-based GSV estimates were consistent and highlighted areas of change. From the two ASAR maps, slight loss of volume from 2005 to 2010 was estimated.
BibTeX:
@conference{Schmullius2013,
  author = {Schmullius, C. and Leiterer, R. and Burjack, I. and Traut, K. and Santoro, M. and Li, Z.Y. and Ling, F.L.},
  title = {Forest dragon 2: Final results of the european partners},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  year = {2013},
  volume = {704 SP},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892682819&partnerID=40&md5=01c4e33b793dd3d8f03ade4d72e7d154}
}
Stahli O, Murk A, Kampfer N, Matzler C and Eriksson P (2013), "Microwave radiometer to retrieve temperature profiles from the surface to the stratopause", Atmospheric Measurement Techniques. Vol. 6(9), pp. 2477-2494.
Abstract: TEMPERA (TEMPERature RAdiometer) is a new ground-based radiometer which measures in a frequency range from 51-57 GHz radiation emitted by the atmosphere. With this instrument it is possible to measure temperature profiles from ground to about 50 km. This is the first ground-based instrument with the capability to retrieve temperature profiles simultaneously for the troposphere and stratosphere. The measurement is done with a filterbank in combination with a digital fast Fourier transform spectrometer. A hot load and a noise diode are used as stable calibration sources. The optics consist of an off-axis parabolic mirror to collect the sky radiation. Due to the Zeeman effect on the emission lines used, the maximum height for the temperature retrieval is about 50 km. The effect is apparent in the measured spectra. The performance of TEMPERA is validated by comparison with nearby radiosonde and satellite data from the Microwave Limb Sounder on the Aura satellite. In this paper we present the design and measurement method of the instrument followed by a description of the retrieval method, together with a validation of TEMPERA data over its first year, 2012. 2013 Author(s).
BibTeX:
@article{Stahli20132477,
  author = {Stahli, O. and Murk, A. and Kampfer, N. and Matzler, C. and Eriksson, P.},
  title = {Microwave radiometer to retrieve temperature profiles from the surface to the stratopause},
  journal = {Atmospheric Measurement Techniques},
  year = {2013},
  volume = {6},
  number = {9},
  pages = {2477-2494},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884832899&doi=10.5194%2famt-6-2477-2013&partnerID=40&md5=c9bd21ea0a6341ef68d024fb5902a8c4},
  doi = {10.5194/amt-6-2477-2013}
}
Strozzi T, Ambrosi C and Raetzo H (2013), "Interpretation of aerial photographs and satellite SAR interferometry for the inventory of landslides", Remote Sensing. Vol. 5(5), pp. 2554-2570.
Abstract: An inventory of landslides with an indication of the state of activity is necessary in order to establish hazard maps. We combine interpretation of aerial photographs and information on surface displacement from satellite Synthetic Aperture Radar (SAR) interferometry for mapping landslides and intensity classification. Sketch maps of landslides distinguished by typology and depth, including geomorphological features, are compiled by stereoscopic photo-interpretation. Results achieved with differential SAR interferometry (InSAR) and Persistent Scatterer Interferometry (PSI) are used to estimate the state of activity of landslides around villages and in sparsely vegetated areas with numerous exposed rocks. For validation and possible extension of the inventory around vegetated areas, where InSAR and PSI failed to retrieve displacement information, traditional monitoring data such as topographic measurements and GPS are considered. Our results, covering extensive areas, are a valuable contribution towards the analysis of landslide hazards in areas where traditional monitoring techniques are sparse or unavailable. In this contribution we discuss our methodology for a study area around the deep-seated landslide in Osco in southern Switzerland. 2013 by the authors.
BibTeX:
@article{Strozzi20132554,
  author = {Strozzi, T. and Ambrosi, C. and Raetzo, H.},
  title = {Interpretation of aerial photographs and satellite SAR interferometry for the inventory of landslides},
  journal = {Remote Sensing},
  year = {2013},
  volume = {5},
  number = {5},
  pages = {2554-2570},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880336746&doi=10.3390%2frs5052554&partnerID=40&md5=afbb70d688d895b2cf4d474bbcbf0279},
  doi = {10.3390/rs5052554}
}
Strozzi T, Teatini P, Tosi L, Wegmüller U and Werner C (2013), "Land subsidence of natural transitional environments by satellite radar interferometry on artificial reflectors", Journal of Geophysical Research: Earth Surface. Vol. 118(2), pp. 1177-1191. Blackwell Publishing Ltd.
Abstract: Land subsidence is a widespread phenomenon, particularly relevant to transitional environments, such as wetlands, deltas, and lagoons, characterized by low elevation with respect to the mean sea level. Satellite synthetic aperture radar (SAR) interferometry offers the possibility to effectively and precisely measure land displacements for dry surfaces or anthropogenic structures, but difficulties arise in identifying long-term stable targets in natural transitional regions. In order to improve the coverage of satellite SAR interferometry in salt marshes within the Venice Lagoon (Italy), we installed a network of 57 Trihedral Corner Reflectors (TCRs). The TCRs were monitored by ENVISAT ASAR and TerraSAR-X acquisitions covering the time period from November 2006 to September 2011. The results show that the northern lagoon basin is subsiding at  3 mm/yr and that the central and southern portions are more stable. Larger subsidence rates, up to 6 mm/yr, are measured where surficial loads, such as artificial salt marshes or embankments, rise above the lagoon bottom. The accuracy of TerraSAR-X is greater than ENVISAT due to the shorter wavelength and higher spatial resolution in relationship to the size of the TCRs. The observations obtained in the Venice Lagoon indicate that SAR interferometry using a large network of artificial reflectors is an effective and powerful methodology to monitor land subsidence in transitional environments where the loss of elevation with respect to the mean sea level can yield significant morphological changes to the natural environment. Key Points Subsidence of natural transitional environments Radar interferometry on artificial corner reflectors Environment deterioration by loss of elevation relative to the mean sea level 2013. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Strozzi20131177,
  author = {Strozzi, T. and Teatini, P. and Tosi, L. and Wegmüller, U. and Werner, C.},
  title = {Land subsidence of natural transitional environments by satellite radar interferometry on artificial reflectors},
  journal = {Journal of Geophysical Research: Earth Surface},
  publisher = {Blackwell Publishing Ltd},
  year = {2013},
  volume = {118},
  number = {2},
  pages = {1177-1191},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880748858&doi=10.1002%2fjgrf.20082&partnerID=40&md5=be11e2bec5d7ae892b87a2f7fe98fa1a},
  doi = {10.1002/jgrf.20082}
}
Tian X, Li Z-Y, Chen E-X, Ling F-L, Cartus O, Santoro M and Schmullius C (2013), "Large-scale forest mapping based on ERS-1/2 and Envisat ASAR data", Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University. Vol. 35(1), pp. 7-15.
Abstract: In this paper, two kinds of forest map over Northeast China were produced by use of archived ERS-1/2 tandem data (1995-2000) and Envisat ASAR data (2005). As far as ERS-1/2 coherence model was concerned, a new approach was introduced, that allowed model training using the MODIS Vegetation Continuous Fields canopy cover product without further need for ground data. On basis of this method, the large-scale forest stem volume map (four classes: 0-20, &gt; 20-50, &gt; 50-80 and &gt; 80 m3/hm2) was generated. As regards the Envisat ASAR data, the object-based classifier was applied to map the forest/non-forest areas automatically. The cross-comparisons were performed for these two kinds of map based on the land use map from Landsat TM-5 data acquired in 2005. The results show that these two satellite SAR data can be used for the large-scale forest mapping and their maps in current case will provide supports for the further analysis of forest change detection and the map updating.
BibTeX:
@article{Tian20137,
  author = {Tian, X. and Li, Z.-Y. and Chen, E.-X. and Ling, F.-L. and Cartus, O. and Santoro, M. and Schmullius, C.},
  title = {Large-scale forest mapping based on ERS-1/2 and Envisat ASAR data},
  journal = {Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University},
  year = {2013},
  volume = {35},
  number = {1},
  pages = {7-15},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872766378&partnerID=40&md5=3eb62f46ba98f054a841a873e118ab4b}
}
Tosi L, Teatini P and Strozzi T (2013), "Natural versus anthropogenic subsidence of Venice", Scientific Reports. Vol. 3
Abstract: We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7âmm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from-10 to 2âmm/yr. These displacements are generally local and distributed along the margins of the city islands.
BibTeX:
@article{Tosi2013,
  author = {Tosi, L. and Teatini, P. and Strozzi, T.},
  title = {Natural versus anthropogenic subsidence of Venice},
  journal = {Scientific Reports},
  year = {2013},
  volume = {3},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885130906&doi=10.1038%2fsrep02710&partnerID=40&md5=8ca1e00610dc698f7162ac29bbf8f07f},
  doi = {10.1038/srep02710}
}
Traut K, Burjack I, Eberle J, Santoro M and Schmullius C (2013), "Creation of a forest dragon geoportal for validating forest growing stock volume maps", In European Space Agency, (Special Publication) ESA SP. Vol. 704 SP
BibTeX:
@conference{Traut2013,
  author = {Traut, K. and Burjack, I. and Eberle, J. and Santoro, M. and Schmullius, C.},
  title = {Creation of a forest dragon geoportal for validating forest growing stock volume maps},
  booktitle = {European Space Agency, (Special Publication) ESA SP},
  year = {2013},
  volume = {704 SP},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892757683&partnerID=40&md5=72bb2810a46843c2fab8e70f6dbf980f}
}
Vassilopoulou S, Sakkas V, Wegmüller U and Capes R (2013), "Long term and seasonal ground deformation monitoring of Larissa Plain (Central Greece) by persistent scattering interferometry", Central European Journal of Geosciences. Vol. 5(1), pp. 61-76.
Abstract: The land subsidence which occurs at the Larissa Basin (Thessaly Plain, Central Greece) is due to various causes including aquifer system compaction. Deformation maps of high spatial resolution deduced by the Persistent Scattering Interferometry (PSI) technique (using radar scenes from ERS and ENVISAT satellites) for the period 1992-2006 were produced to study the spatial and temporal ground deformation. A developed GIS database (including geological, tectonic, morphological, hydrological, meteorological and watertable variation from wells in the area) offered the possibility of studying in detail the intense subsidence. The PSI based average deformation image clearly shows that subsidence generally takes place inside the Larissa Plain ranging from 5-250 mm. The largest amplitude rates (-25 mm/yr) are observed around the urban area of Larissa City (especially at Gianouli and Nikea villages), while the Larissa City center appears to be relatively stable with a tendency to subside. The rest of the plain regions seem to subside at moderate rates (about 5-10 mm/yr). The surrounding mountainous area is stable, or has slightly been uplifted with respect to the NE located reference point. It was found that there is a correlation between the seasonal water-table variation (deduced from wells data), the seasonal water demand for irrigation associated with specific types of cultivation (cotton fields), the monthly rainfall, and the observed subsidence rate in the rural regions of the Thessaly Plain. 2013 Versita Warsaw and Springer-Verlag Wien.
BibTeX:
@article{Vassilopoulou201361,
  author = {Vassilopoulou, S. and Sakkas, V. and Wegmüller, U. and Capes, R.},
  title = {Long term and seasonal ground deformation monitoring of Larissa Plain (Central Greece) by persistent scattering interferometry},
  journal = {Central European Journal of Geosciences},
  year = {2013},
  volume = {5},
  number = {1},
  pages = {61-76},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875181204&doi=10.2478%2fs13533-012-0115-x&partnerID=40&md5=da516f2927375cbececcfe261e1ce3d1},
  doi = {10.2478/s13533-012-0115-x}
}
Wegmüller U, Strozzi T, Gruner U, Gisler C and Hauser M (2013), "Displacement measurements by means of satellite radar in the upper Reuss Valley in the North-South transport axis in the period 1992-2010 [Verschiebungsmessungen mittels Satellitenradar im Urner Reusstal oberhalb der Nord-Sued-Verkehrsachse im Zeitraum 1992 - 2010]", Bulletin fuer Angewandte Geologie. Vol. 18(2), pp. 139-153. Ver. Schweizerischer Petroleum Geol. und Ing..
Abstract: In a pilot project SAR interferometry was used to determine ground displacement measurements in the upper Reuss valley (Switzerland] between Sisikon and Wassen, with a special focus on the area of the Chli Windgaellen. In an interferometrie time series analysis on 82 acquisitions of the ERS and ENVISAT satellites between 1992 and 2010 terrain displacements were determined and used as input to geological interpretation. The method works without installation of measurement points and achieves for linear movements a precision of about 1 mm/year at a spatial resolution of about 20 m. The spatial coverage is limited by temporal decorrelation of the radar signals by vegetation and by radar specific imaging effects on steep slopes. The method can perfectly be used for the identification of large deformation areas and to monitor past and current movements, permitting to use it as an efficient component of an early warning system.
BibTeX:
@article{Wegmuller2013139,
  author = {Wegmüller, U. and Strozzi, T. and Gruner, U. and Gisler, C. and Hauser, M.},
  title = {Displacement measurements by means of satellite radar in the upper Reuss Valley in the North-South transport axis in the period 1992-2010 [Verschiebungsmessungen mittels Satellitenradar im Urner Reusstal oberhalb der Nord-Sued-Verkehrsachse im Zeitraum 1992 - 2010]},
  journal = {Bulletin fuer Angewandte Geologie},
  publisher = {Ver. Schweizerischer Petroleum Geol. und Ing.},
  year = {2013},
  volume = {18},
  number = {2},
  pages = {139-153},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006359777&doi=10.5169%2fseals-391153&partnerID=40&md5=19f07ceb2172fece0c2cd598c47f4820},
  doi = {10.5169/seals-391153}
}
Barboux C, Delaloye R, Strozzi T, Lambiel C, Collet C and Raetzo H (2012), "Monitoring active rock glaciers in the Western Swiss Alps: Challenges of Differential Sar Interferometry and solutions to estimate annual and seasonal displacement rates", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 5210-5213.
Abstract: This paper describes a new method to monitor active rock glaciers using DInSAR technique with Terrasar-X data acquired with mode facing slope and 11 days time interval during late summers 2009 to 2011. Where the spatial distribution of the rock glacier surface deformation derived from the DInSAR data using conventional unwrapping processes fails due to the relative small size and the complex movement of some rock glaciers, a specific profile is here defined through the rock glacier and is used to analyze the DInSAR products along it. Firstly, the prerequisites to perform such analysis at local scale are given. Then a quantification and discussion of results are achieved through different examples of active rock glaciers encountered in Western Swiss Alps. 2012 IEEE.
BibTeX:
@conference{Barboux20125210,
  author = {Barboux, C. and Delaloye, R. and Strozzi, T. and Lambiel, C. and Collet, C. and Raetzo, H.},
  title = {Monitoring active rock glaciers in the Western Swiss Alps: Challenges of Differential Sar Interferometry and solutions to estimate annual and seasonal displacement rates},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {5210-5213},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873207972&doi=10.1109%2fIGARSS.2012.6352435&partnerID=40&md5=c4e7398379970a8f95458c06461af046},
  doi = {10.1109/IGARSS.2012.6352435}
}
Cartus O, Kellndorfer J, Rombach M and Walker W (2012), "Mapping canopy height and growing stock volume using airborne lidar, alos palsar and landsat ETM+", Remote Sensing. Vol. 4(11), pp. 3320-3345.
Abstract: We have investigated for forest plantations in Chile the stand-level retrieval of canopy height (CH) and growing stock volume (GSV) using Airborne Laser Scanner (ALS), ALOS PALSAR and Landsat. In a two-stage up-scaling approach, ensemble regression tree models (randomForest) were used to relate a suite of ALS canopy structure indices to stand-level in situ measurements of CH and GSV for 319 stands. The retrieval of CH and GSV with ALS yielded high accuracies with R2s of 0.93 and 0.81, respectively. A second set of randomForest models was developed using multi-temporal ALOS PALSAR intensities and repeat-pass coherences in two polarizations as well as Landsat data as predictor and stand-level ALS based estimates of CH and GSV as response variables. At three test sites, the retrieval of CH and GSV with PALSAR/Landsat reached promising accuracies with R2s in the range of 0.7 to 0.85. We show that the combined use of multi-temporal PALSAR intensity, coherence and Landsat yields higher retrieval accuracies than the retrieval with any of the datasets alone. Potential limitations for the large-area application of the fusion approach included (1) the low sensitivity of ALS first/last return data to forest horizontal structure, affecting the retrieval of GSV in less managed types of forest, and (2) the dense ALS sampling required to achieve high retrieval accuracies at larger scale. 2012 by the authors.
BibTeX:
@article{Cartus20123320,
  author = {Cartus, O. and Kellndorfer, J. and Rombach, M. and Walker, W.},
  title = {Mapping canopy height and growing stock volume using airborne lidar, alos palsar and landsat ETM+},
  journal = {Remote Sensing},
  year = {2012},
  volume = {4},
  number = {11},
  pages = {3320-3345},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84870835634&doi=10.3390%2frs4113320&partnerID=40&md5=45859392a5c13f8d2bb7e30236c7ecc9},
  doi = {10.3390/rs4113320}
}
Cartus O, Santoro M and Kellndorfer J (2012), "Mapping forest aboveground biomass in the Northeastern United States with ALOS PALSAR dual-polarization L-band", Remote Sensing of Environment. Vol. 124, pp. 466-478.
Abstract: A method for regional scale mapping of aboveground forest biomass with Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data is presented. A fully automated algorithm, exploiting the synergy of SAR and optical remote sensing for the calibration of a semi-empirical model (Santoro et al., 2011; Cartus et al., 2011), was adopted to map forest aboveground biomass with L-band HH and HV intensity in the northeastern United States. In the retrieval algorithm, a semi-empirical model is calibrated and inverted for each HH and HV image to estimate biomass at the pixel level. Where possible, biomass estimates for single images in a multi-temporal stack were combined in a weighted manner. A comparison with the National Biomass and Carbon Dataset, NBCD 2000 (Kellndorfer et al., in preparation), at different spatial scales indicated the feasibility of the automated biomass retrieval approach and confirmed previous findings that the retrieval accuracy for HV intensity is consistently better than that for HH intensity and depends on the imaging conditions. The weighted combination of the biomass estimates from each intensity image in a multi-temporal stack significantly improved the retrieval performance. Because of regional differences in the multi-temporal coverage with ALOS PALSAR dual polarization data (1-5 images for 2007/08) and the pronounced dependence of the retrieval for single images on the imaging conditions, the possibility of producing maps with consistent accuracy at high resolution was found to be limited. Accurate biomass estimates were obtained when aggregating the ALOS biomass maps at county scale and comparing the estimates to Forest Inventory and Analysis (FIA) county statistics (RMSE=12.9t/ha, R2=0.86). 2012 Elsevier Inc.
BibTeX:
@article{Cartus2012466,
  author = {Cartus, O. and Santoro, M. and Kellndorfer, J.},
  title = {Mapping forest aboveground biomass in the Northeastern United States with ALOS PALSAR dual-polarization L-band},
  journal = {Remote Sensing of Environment},
  year = {2012},
  volume = {124},
  pages = {466-478},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863193261&doi=10.1016%2fj.rse.2012.05.029&partnerID=40&md5=a3e28524461e6659fd0481005bcafdbd},
  doi = {10.1016/j.rse.2012.05.029}
}
Dimitrov M, Kostov K, Jonard F, Jadoon K, Schwank M, Weihermuller L, Hermes N, Vanderborght J and Vereecken H (2012), "New improved algorithm for sky calibration of L-band radiometers JLBARA and ELBARA II", In 2012 12th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad 2012 - Proceedings.
Abstract: We propose a new algorithm for sky calibration of the L-band radiometers JLBARA and ELBARA II, introducing the effective transmissivities of the instruments. The suggested approach was tested using experimental data obtained at the Selhausen test site, Germany. It was shown that for JLBARA the effective transmissivities depend strongly on the air temperature and decrease with increasing air temperature, while for ELBARA II such strong dependence was not observed. It was also shown that the effective transmissivities account for the antenna and feed cable loss effects, and for the variations of the radiometer gain due to air temperature changes. The new calibration algorithm reduces significantly the bias of brightness temperature estimates for both radiometers, especially for JLBARA. 2012 IEEE.
BibTeX:
@conference{Dimitrov2012,
  author = {Dimitrov, M. and Kostov, K.G. and Jonard, F. and Jadoon, K.Z. and Schwank, M. and Weihermuller, L. and Hermes, N. and Vanderborght, J. and Vereecken, H.},
  title = {New improved algorithm for sky calibration of L-band radiometers JLBARA and ELBARA II},
  booktitle = {2012 12th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad 2012 - Proceedings},
  year = {2012},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860763004&doi=10.1109%2fMicroRad.2012.6185259&partnerID=40&md5=1531c1143f6e9b73e2f0d953366abec3},
  doi = {10.1109/MicroRad.2012.6185259}
}
Dixon T, Voytenko D, Lembke C, De La Pea S, Howat I, Gourmelen N, Werner C and Oddsson B (2012), "Emerging technology monitors ice-sea interface at outlet glaciers", Eos. Vol. 93(48), pp. 497-498.
Abstract: Recent melting in Greenland and Antarctica has led to concerns about the long-term stability of these ice sheets and their potential contributions to future sea level rise. Marine-terminating outlet glaciers play a key role in the dynamics of these ice sheets; recent mass losses are likely related to increased influx of warmer water to the base of outlet glaciers, as evidenced by the fact that changes in ocean currents, calving front retreats, glacial thinning, mass redistribution based on satellite gravity data, and accelerating coastal uplift are roughly concurrent [e.g., Holland et al., 2008; Wouters et al., 2008; Jiang et al., 2010; Straneo et al., 2012; Bevis et al., 2012]. However, collecting quantitative measurements within the dynamic environment of marine outlet glaciers is challenging. Oceanographic measurements are limited in iceberg-laden fjords. Measuring ice flow speeds near the calving front is similarly challenging; satellite methods lack temporal resolution (satellite revisit times are several days or longer), while GPS gives limited spatial resolution, a problem for assessing changes near the highly variable calving front. 2012. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Dixon2012497,
  author = {Dixon, T.H. and Voytenko, D. and Lembke, C. and De La Pea, S. and Howat, I. and Gourmelen, N. and Werner, C. and Oddsson, B.},
  title = {Emerging technology monitors ice-sea interface at outlet glaciers},
  journal = {Eos},
  year = {2012},
  volume = {93},
  number = {48},
  pages = {497-498},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84870574116&doi=10.1029%2f2012EO480001&partnerID=40&md5=7d7217d76980af3289174af78ab493af},
  doi = {10.1029/2012EO480001}
}
Eriksson L, Fransson J, Soja M and Santoro M (2012), "Backscatter signatures of wind-thrown forest in satellite SAR images", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 6435-6438.
Abstract: Two field experiments have been conducted in Sweden to allow an evaluation of the backscatter signatures of wind-thrown forest from L-band, C-band and X-band Synthetic Aperture Radar. When the trees are felled the backscattered signal from TerraSAR-X (X-band) increase with about 1.5 dB, while for ALOS PALSAR (L-band) a decrease with the same amount is observed. Radar images with fine spatial resolution also show shadowing effects that should be possible to use for identification of storm felled forest. 2012 IEEE.
BibTeX:
@conference{Eriksson20126435,
  author = {Eriksson, L.E.B. and Fransson, J.E.S. and Soja, M.J. and Santoro, M.},
  title = {Backscatter signatures of wind-thrown forest in satellite SAR images},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {6435-6438},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873101723&doi=10.1109%2fIGARSS.2012.6352732&partnerID=40&md5=d0f0cabcf587e7a4b56eae874c918ea2},
  doi = {10.1109/IGARSS.2012.6352732}
}
Frey H, Paul F and Strozzi T (2012), "Compilation of a glacier inventory for the western Himalayas from satellite data: Methods, challenges, and results", Remote Sensing of Environment. Vol. 124, pp. 832-843.
Abstract: Due to their sensitive reaction to changes in climatic conditions, glaciers have been selected as an essential climate variable (ECV). Although a large amount of ice is located in the Himalayas, this region is yet only sparsely represented in global glacier databases. Accordingly, a sound and comprehensive change assessment or determination of water resources was not yet possible. In this study, we present a new glacier inventory for the western Himalayas, compiled from Landsat ETM+ scenes acquired between 2000 and 2002, coherence images from ALOS PALSAR image pairs, the SRTM digital elevation model (DEM) and the ASTER Global DEM (GDEM). Several specific challenges for glacier mapping were found in this region and addressed. They are related to debris cover, orographic clouds, locally variable snow conditions, and creeping permafrost features in cold-dry regions. Additional to seven topographic parameters that are obtained from the ASTER GDEM for each glacier, we also determined the relative amount of debris cover on the glacier surface. The inventory contains 11,400 glaciers larger than 0.02km2, which cover a total area of 9,310km2. Analysis of the inventory data revealed characteristic patterns of mean glacier elevation and relative debris cover amounts that might be related to the governing climatic conditions. The full dataset will be freely available in the GLIMS glacier database to foster further analyses and modeling of the glaciers in this region. 2012 Elsevier Inc.
BibTeX:
@article{Frey2012832,
  author = {Frey, H. and Paul, F. and Strozzi, T.},
  title = {Compilation of a glacier inventory for the western Himalayas from satellite data: Methods, challenges, and results},
  journal = {Remote Sensing of Environment},
  year = {2012},
  volume = {124},
  pages = {832-843},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864102237&doi=10.1016%2fj.rse.2012.06.020&partnerID=40&md5=7809343b96693af7a17b75f39860c94d},
  doi = {10.1016/j.rse.2012.06.020}
}
Frey O, Meier E and Hajnsek I (2012), "Towards a more reliable estimation of forest parameters from polarimetric SAR tomography data", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3110-3113.
Abstract: In this contribution, tomographic imagery obtained from estimating the 3-D localization and the polarimetric signature of backscattering sources within a forest environment from fully-polarimetric multibaseline SAR data at L- and P-bands are presented. Both, polarization diversity and spatial diversity were exploited jointly within the tomographic focusing to estimate the targets' localization and polarimetric signature. We thereby extend our recently proposed time-domain back-projection (TDBP)-based tomographic focusing approach. The tomographic slices obtained from polarimetric spectral estimation using MLBF, Capon, and MUSIC are opposed to the results previously obtained by tomographic focusing of the individual polarization channels. The results are briefly discussed with respect to potential advancements towards more reliable estimation of forest parameters from SAR tomography data. 2012 IEEE.
BibTeX:
@conference{Frey20123110,
  author = {Frey, O. and Meier, E. and Hajnsek, I.},
  title = {Towards a more reliable estimation of forest parameters from polarimetric SAR tomography data},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3110-3113},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873147971&doi=10.1109%2fIGARSS.2012.6350767&partnerID=40&md5=146b724be5c2b473425d064715201fe2},
  doi = {10.1109/IGARSS.2012.6350767}
}
Frey O, Meier E and Hajnsek I (2012), "Tweaking baseline constellations for airborne SAR tomography and InSAR: An experimental study at L-and P-bands", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2012-April, pp. 215-218. Institute of Electrical and Electronics Engineers Inc..
Abstract: A notable obstacle hindering widespread application of SAR tomography for 3D mapping of vegetation is the relatively large number of acquisitions that are needed to obtain a high resolution and a good rejection of spurious responses in the direction perpendicular to the line of sight. In this paper, we discuss the impact of different baseline constellations on 3-D mapping of vegetation volumes and the underlying topography in terms of tomographic focusing as well as classical single-baseline repeat-pass interferometry. The effects are studied using two airborne tomography data sets at L-and P-bands.
BibTeX:
@conference{Frey2012215,
  author = {Frey, O. and Meier, E. and Hajnsek, I.},
  title = {Tweaking baseline constellations for airborne SAR tomography and InSAR: An experimental study at L-and P-bands},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2012},
  volume = {2012-April},
  pages = {215-218},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026213191&partnerID=40&md5=efbfbcafd78aa563efdb7ccaf8b18b01}
}
Frey O, Wegmüller U and Werner C (2012), "Terrain motion measurements over European urban areas using Persistent Scatterer Interferometry", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 7565-7568.
Abstract: In this contribution Persistent Scatterer Interferometry (PSI) processings done in the framework of the FP7 Project PanGEO over a number of European sites are presented. After a short introduction of the PanGEO project, we present the data used, the processing done and the results of the PSI analysis. The influence of specifics as the presence of large non-urban areas, significant topography, seasonal effects, special deformation characteristics, and the size of the available data stacks on the processing are highlighted. 2012 IEEE.
BibTeX:
@conference{Frey20127565,
  author = {Frey, O. and Wegmüller, U. and Werner, C.},
  title = {Terrain motion measurements over European urban areas using Persistent Scatterer Interferometry},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {7565-7568},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873109224&doi=10.1109%2fIGARSS.2012.6351911&partnerID=40&md5=6a67c0384041d145eb179995ddcf057b},
  doi = {10.1109/IGARSS.2012.6351911}
}
Graham E, N'Dri Koffi E and Matzler C (2012), "An observational study of air and water vapour convergence over the Bernese Alps, Switzerland, during summertime and the development of isolated thunderstorms", Meteorologische Zeitschrift. Vol. 21(6), pp. 561-574.
Abstract: The daytime summer phenomenon of the mesoscale transport of air and water vapour from the Swiss lowlands into the nearby western Alps, leading to orographic convection, is investigated using a range of independent observations. These observations are: Global Positioning System (GPS) integrated water vapour (IWV) data, the TROWARA microwave radiometer, MeteoSwiss ANETZ surface weather station data, the Payerne radiosonde, synoptic analyses for Switzerland and Europe, EUMETSAT and NOAA visible and infra-red satellite images, MeteoSwiss operational precipitation radar, photographs and webcam images including time-lapse cloud animations. The intention was to show, using GPS IWV data, that significant differences in IWV may occur between the Swiss plain and nearby Alps during small single-cell Alpine thunderstorm events, and that these may be attributable to regional airflow convergence. Two particular case studies are presented for closer examination: 20 June 2005 and 13 June 2006. On both days, fine and warm weather was followed by isolated orographic convection over the Alps in the afternoon and evening, producing thunderstorms. The thunderstorms investigated were generally small, local, discrete and shortlived phenomena. They were selected for study because of almost stationary position over orography, rendering easy observation because they remained contained within a particular mountain region before dissipating. The results show that large transfers of air and water vapour occur from the Swiss plain to the mountains on such days, with up to a 50% increase in GPS IWV values at individual Alpine stations, coincident with strong airflow convergence in the same locality. 2012 by Gebruer Borntraeger.
BibTeX:
@article{Graham2012561,
  author = {Graham, E. and N'Dri Koffi, E. and Matzler, C.},
  title = {An observational study of air and water vapour convergence over the Bernese Alps, Switzerland, during summertime and the development of isolated thunderstorms},
  journal = {Meteorologische Zeitschrift},
  year = {2012},
  volume = {21},
  number = {6},
  pages = {561-574},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874594002&doi=10.1127%2f0941-2948%2f2012%2f0347&partnerID=40&md5=982768345644c88c591c3f23cb0b33c1},
  doi = {10.1127/0941-2948/2012/0347}
}
Henke D, Magnard C, Frioud M, Small D, Meier E and Schaepman M (2012), "Moving-target tracking in single-channel wide-beam SAR", IEEE Transactions on Geoscience and Remote Sensing. Vol. 50(11 PART2), pp. 4735-4747. Institute of Electrical and Electronics Engineers Inc..
Abstract: A novel method for moving-target tracking using single-channel synthetic aperture radar (SAR) with a large antenna beamwidth is introduced and evaluated using a field experiment and real SAR data. The presented approach is based on subaperture SAR processing, image statistics, and multitarget unscented Kalman filtering. The method is capable of robustly detecting and tracking moving objects over time, providing information not only about the existence of moving targets but also about their trajectories in the image space while illuminated by the radar beam. We have successfully applied the method on an experimental data set using miniature SAR to accurately characterize the movement of vehicles on a highway section in the radar image space. 1980-2012 IEEE.
BibTeX:
@article{Henke20124735,
  author = {Henke, D. and Magnard, C. and Frioud, M. and Small, D. and Meier, E. and Schaepman, M.E.},
  title = {Moving-target tracking in single-channel wide-beam SAR},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2012},
  volume = {50},
  number = {11 PART2},
  pages = {4735-4747},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869496515&doi=10.1109%2fTGRS.2012.2191561&partnerID=40&md5=edc322e9a93876100f12eb7d4b940f2e},
  doi = {10.1109/TGRS.2012.2191561}
}
Jonard F, Weihermuller L, Schwank M, Jadoon K, Vereecken H and Lambot S (2012), "Estimating soil hydraulic properties using L-band radiometer and ground-penetrating radar", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 706-709.
Abstract: In this study, we experimentally analyze the feasibility of estimating the soil hydraulic properties from L-band radiometer and ground-penetrating radar (GPR) data. L-band radiometer and ultrawideband off-ground GPR measurements were performed above a sand box in hydrostatic equilibrium with a water table located at different depths. The results of the inversions showed that the radar and radiometer signals contain sufficient information to estimate the soil water retention curve and its related hydraulic parameters with a relatively good accuracy compared to time-domain reflectometry estimates. However, an accurate estimation of the hydraulic parameters was only obtained by considering the saturated water content parameter as known during the inversion. 2012 IEEE.
BibTeX:
@conference{Jonard2012706,
  author = {Jonard, F. and Weihermuller, L. and Schwank, M. and Jadoon, K.Z. and Vereecken, H. and Lambot, S.},
  title = {Estimating soil hydraulic properties using L-band radiometer and ground-penetrating radar},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {706-709},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873172004&doi=10.1109%2fIGARSS.2012.6351467&partnerID=40&md5=5672eb556aa8df81aeadf1de1ea3c229},
  doi = {10.1109/IGARSS.2012.6351467}
}
Kourkouli P, Strozzi T and Wegmüller U (2012), "Comparison of DInSAR and persistent scatterer interferometry for ground-motion monitoring in the Venice lagoon", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3919-3922.
Abstract: The city of Venice (Italy) and its surrounding lagoon constitutes a unique worldwide environment vulnerable to loss of surface elevation due to land subsidence and sea level rise. Locally, the city of Venice, shows a present general stability with rates averaging between -1 to +1 mm/year. This work presents results over Venice area, derived by the two interferometric techniques (DInSAR and Permanent Scatterers Interferometry). The use of the two techniques allows us to understand the complementarity of both techniques and their limitations. 2012 IEEE.
BibTeX:
@conference{Kourkouli20123919,
  author = {Kourkouli, P. and Strozzi, T. and Wegmüller, U.},
  title = {Comparison of DInSAR and persistent scatterer interferometry for ground-motion monitoring in the Venice lagoon},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3919-3922},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873191691&doi=10.1109%2fIGARSS.2012.6350555&partnerID=40&md5=27de4279d40a572ecacb1b9b30d713eb},
  doi = {10.1109/IGARSS.2012.6350555}
}
Magnard C, Brehm T, Essen H and Meier E (2012), "High resolution MEMPHIS SAR data processing and applications", In Progress in Electromagnetics Research Symposium. , pp. 328-332.
Abstract: This paper focuses on MEMPHIS (Multi-frequency Experimental Monopulse High- resolution Interferometric SAR) data processing, possible applications using its various SAR modes and the results obtained. The processing chain used to focus MEMPHIS data is presented. To demonstrate the focusing quality, the signatures of corner reflectors were analyzed, revealing not only a high resolution, but also a very precise geometric positioning accuracy on the order of the resolution, in spite of MEMPHIS' experimental and portable design. Finally, applications and results using the various antennas are presented, such as the generation of digital surface models with the multi-baseline interferometric antenna along with a quality evaluation, as well as channel combinations of the polarimetric data.
BibTeX:
@conference{Magnard2012328,
  author = {Magnard, C. and Brehm, T. and Essen, H. and Meier, E.},
  title = {High resolution MEMPHIS SAR data processing and applications},
  booktitle = {Progress in Electromagnetics Research Symposium},
  year = {2012},
  pages = {328-332},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84868594572&partnerID=40&md5=9be975800957c18f8f209d8dc6c7d283}
}
Manconi A and Casu F (2012), "Joint analysis of displacement time series retrieved from SAR phase and amplitude: Impact on the estimation of volcanic source parameters", Geophysical Research Letters. Vol. 39(14) Blackwell Publishing Ltd.
Abstract: We study the impact of jointly analyzing the phase and amplitude information of a SAR dataset on the interpretation of the surface displacement over time in areas characterized by large dynamics. In particular, we compute the ground displacement time series over Fernandina and Sierra Negra calderas (Galápagos islands), by applying the Small BAseline Subset (SBAS) and the Pixel Offset (PO)-SBAS techniques to 25 ENVISAT SAR images acquired between 2003 and 2007, when both volcanoes experienced catastrophic eruptions. By merging the SBAS and PO-SBAS time series results the spatial density of measurements increased substantially. In addition, the joint analysis of the time series allows us to better constrain the temporal evolution of the magmatic source volume changes. Our results show that the joint use of the SBAS and PO-SBAS approaches may help for a more correct evaluation of large deformation affecting the Earth's surface caused by eruptions, earthquakes, and landslide phenomena. 2012. American Geophysical Union.
BibTeX:
@article{Manconi2012,
  author = {Manconi, A. and Casu, F.},
  title = {Joint analysis of displacement time series retrieved from SAR phase and amplitude: Impact on the estimation of volcanic source parameters},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2012},
  volume = {39},
  number = {14},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864444179&doi=10.1029%2f2012GL052202&partnerID=40&md5=b3ea153ff5452bf7cc50b1889e1bd496},
  doi = {10.1029/2012GL052202}
}
Manconi A, Giordan D, Allasia P, Baldo M and Lollino G (2012), "Surface displacements following the Mw 6.3 L'Aquila earthquake: One year of continuous monitoring via Robotized Total Station", Italian Journal of Geosciences. Vol. 131(3), pp. 403-409.
Abstract: We present the results of a continuous monitoring of the surface displacements following the April 6th 2009 L'Aquila earthquake in the area of Paganica village, central Italy. We considered 3-dimensional displacements measured via Robotized Total Station (RTS) installed the April 24th 2009 in the area of Paganica village (ca. 5 km ENE from L'Aquila town), where a water pipeline located within the urban centre was severely damaged. The monitoring system was set up in order to reveal potential post-seismic displacements that could cause further damages to the water pipeline. The RTS ran continuously for about one year, with sampling rates varying from 2 to 4 hours, and measured displacements at selected point targets. The revealed surface displacements are in agreement with the results of a DInSAR time series analysis relevant to satellite SAR data acquired over the same area and time period by the Italian satellite's constellation Cosmo-SkyMed. Moreover, despite the RTS monitored area was spatially limited, our analyses provide detailed feedbacks on fault processes following the L'Aquila earthquake. The aftershocks temporal evolution and the post-seismic displacements measured in the area show very similar exponential decays over time, with estimated cross-correlation coefficients values ranging from 0.86 to 0.97. The results of our time dependent modelling of the RTS measurements suggest that L'Aquila earthquake post-seismic displacements were dominated by the fault afterslip and/or fault creep, while poroelastic and viscoelastic processes had negligible effects. 2012 Societa Geologica Italiana, Roma.
BibTeX:
@article{Manconi2012403,
  author = {Manconi, A. and Giordan, D. and Allasia, P. and Baldo, M. and Lollino, G.},
  title = {Surface displacements following the Mw 6.3 L'Aquila earthquake: One year of continuous monitoring via Robotized Total Station},
  journal = {Italian Journal of Geosciences},
  year = {2012},
  volume = {131},
  number = {3},
  pages = {403-409},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84868627411&doi=10.3301%2fIJG.2012.13&partnerID=40&md5=439fd57201e577bebce96fdd280873b3},
  doi = {10.3301/IJG.2012.13}
}
Marzahn P, Rieke-Zapp D, Wegmüller U and Ludwig R (2012), "Multidimensional roughness characterization for microwave remote sensing applications using a simple photogrammetric acquisition system", In International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives. Vol. 39, pp. 423-428. International Society for Photogrammetry and Remote Sensing.
Abstract: Soil surface roughness, as investigated in this study, is a critical parameter in microwave remote sensing. As soil surface roughness is treated as a stationary single scale isotropic process in most backscattering models, the overall objective of this study was to better understand the role of soil surface roughness in the context of backscattering. Therefore a simple photogrametric acquisition setup was developed for the characterization of soil surface roughness. In addition several suited SAR images of different sensors (ERS-2 and TerraSAR-X) were acquired to quantify the impact of soil surface roughness on the backscattered signal. Major progress achieved in this work includes the much improved characterization of in-field soil surface roughness. Good progress was also made in the understanding of backscattering from bare surface in the case of directional scattering.
BibTeX:
@conference{Marzahn2012423,
  author = {Marzahn, P. and Rieke-Zapp, D. and Wegmüller, U. and Ludwig, R.},
  editor = {Shortis M., Mills J.},
  title = {Multidimensional roughness characterization for microwave remote sensing applications using a simple photogrammetric acquisition system},
  booktitle = {International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives},
  publisher = {International Society for Photogrammetry and Remote Sensing},
  year = {2012},
  volume = {39},
  pages = {423-428},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84924237581&partnerID=40&md5=ce8e7dfed698cfba2ca9e3afd92249e9}
}
Marzahn P, Wegmüller U, Mattia F and Ludwig R (2012), "'Flashing Fields' and the impact of soil surface roughness", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 6963-6966.
Abstract: In this paper the results of an additional campaign in the context of Flashing Fields are presented showing the impact of soil surface roughness on the directional backscattering. For the characterization of soil surface roughness a photogrametric measurement device was used and roughness was measured simultaneous to SAR observation made by ERS-2 and TerraSAR-X. As this study mainly confirmed and consolidated the findings of the previous Flashing Fields studies, major progress was made in in the understanding of the impact of soil surface roughness on the flashing phenomenon. It could be concluded, that besides the row orientation, certain roughness conditions could significantly alter the flashing effect. 2012 IEEE.
BibTeX:
@conference{Marzahn20126963,
  author = {Marzahn, P. and Wegmüller, U. and Mattia, F. and Ludwig, R.},
  title = {'Flashing Fields' and the impact of soil surface roughness},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {6963-6966},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873191097&doi=10.1109%2fIGARSS.2012.6351968&partnerID=40&md5=77014391ac8162963727fff0909c26a8},
  doi = {10.1109/IGARSS.2012.6351968}
}
Papke J, Strozzi T, Wiesmann A, Wegmueller U and Tate N (2012), "Rock glacier monitoring with spaceborne SAR in Graechen, Valais, Switzerland", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3911-3914.
Abstract: Spaceborne techniques to monitor the Earth and its processes have advanced significantly over the last thirty years. Sensor spatial resolutions have increased supporting more detailed measurements and shorter revisit times have given higher temporal resolutions. Notwithstanding such advances, understanding the Earth system as a whole remains challenging. The focus of this paper is on monitoring rock glaciers in a mountainous area in the municipality of Graechen, Valais, Switzerland using Envisat and TerraSAR-X data acquired in 2008, 2009 and 2010. Spaceborne Synthetic Aperture Radar interferometry (InSAR) is used to augment existing observations from borehole measurements, geodetic and photogrammetric methods. In the Graechen study area, significant phase differences are reliably observed in 11-day TerraSAR-X and 35-day Envisat differential interferograms related to movements of the 'Distelhorn' rock glacier and the Ritigraben rock glacier. The number of visible fringes are a relatively clear indication for seasonal variations in the movement of the rock glaciers, being about a quarter of a fringe faster in autumn (September/October) than in summer (June, July). 2012 IEEE.
BibTeX:
@conference{Papke20123911,
  author = {Papke, J. and Strozzi, T. and Wiesmann, A. and Wegmueller, U. and Tate, N.J.},
  title = {Rock glacier monitoring with spaceborne SAR in Graechen, Valais, Switzerland},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3911-3914},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873180599&doi=10.1109%2fIGARSS.2012.6350557&partnerID=40&md5=c4dac17389e2c6c877b6c10ec3068daf},
  doi = {10.1109/IGARSS.2012.6350557}
}
Paul F, Bolch T, Kaab A, Nagler T, Shepherd A and Strozzi T (2012), "Satellite-based glacier monitoring in the ESA project Glaciers-CCI", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3222-3225.
Abstract: Glaciers and their changes have been in the focus of the public and the media over the past decade, as they reflect impacts of climate change in an extraordinarily clear and understandable way. They are thus considered as key indicators of climate change and play a most important role in globally coordinated climate-related monitoring programs like the Global Climate Observing System (GCOS). Glacier changes are widely reported with related adverse impacts when errors occur [4]. In consequence, all measurements must be performed with great care and should have been quality checked. Complementary to the field-based observations of changes in glacier length and mass on selected glaciers world-wide [12], satellite data offer the unique possibility to cover entire mountain ranges with a consistent method and thus help creating a more complete and representative picture of ongoing changes. From the large number of possible glacier observations that can be made with (repeat) satellite data, the Glaciers-cci project is focusing on three of them: Glacier area, elevation changes and velocity fields. The characteristics of the satellite sensors used to derive these three products are rather complimentary in regard to spectral properties (optical, microwave, LIDAR), spatial resolution, temporal coverage, repeat interval, etc. Glaciological studies greatly benefit from this wealth of data types and can utilize the different possibilities to derive specific properties of glaciers. 2012 IEEE.
BibTeX:
@conference{Paul20123222,
  author = {Paul, F. and Bolch, T. and Kaab, A. and Nagler, T. and Shepherd, A. and Strozzi, T.},
  title = {Satellite-based glacier monitoring in the ESA project Glaciers-CCI},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3222-3225},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873131965&doi=10.1109%2fIGARSS.2012.6350738&partnerID=40&md5=923688a87daf414357019c1be0afe79b},
  doi = {10.1109/IGARSS.2012.6350738}
}
Santoro M, Pantze A, Fransson J, Dahlgren J and Persson A (2012), "Nation-wide clear-cut mapping in Sweden using ALOS PALSAR strip images", Remote Sensing. Vol. 4(6), pp. 1693-1715.
Abstract: Advanced Land Observing Satellite (ALOS) Phased Array L-band type Synthetic Aperture Radar (PALSAR) backscatter images with 50 m pixel size (strip images) at HV-polarization were used to map clear-cuts at a regional and national level in Sweden. For a set of 31 clear-cuts, on average 59.9% of the pixels within each clear-cut were correctly detected. When compared with a one-pixel edge-eroded version of the reference dataset, the accuracy increased to 88.9%. With respect to statistics from the Swedish Forest Agency, county-wise clear-felled areas were underestimated by the ALOS PALSAR dataset (between 25% and 60%) due to the coarse resolution. When compared with statistics from the Swedish National Forest Inventory, the discrepancies were larger, partly due to the estimation errors from the plot-wise forest inventory data. In Sweden, for the time frame of 2008-2010, the total area felled was estimated to be 140,618 ha, 172,532 ha and 194,586 ha using data from ALOS PALSAR, the Swedish Forest Agency and the Swedish National Forest Inventory, respectively. ALOS PALSAR strip images at HV-polarization appear suitable for detection of clear-felled areas at a national level; nonetheless, the pixel size of 50 m is a limiting factor for accurate delineation of clear-felled areas. 2012 by the authors.
BibTeX:
@article{Santoro20121693,
  author = {Santoro, M. and Pantze, A. and Fransson, J.E.S. and Dahlgren, J. and Persson, A.},
  title = {Nation-wide clear-cut mapping in Sweden using ALOS PALSAR strip images},
  journal = {Remote Sensing},
  year = {2012},
  volume = {4},
  number = {6},
  pages = {1693-1715},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865014962&doi=10.3390%2frs4061693&partnerID=40&md5=588006d0fe059fdd70e8c8195ad1c556},
  doi = {10.3390/rs4061693}
}
Santoro M, Schmullius C, Pathe C and Schwilk J (2012), "Pan-boreal mapping of forest growing stock volume using hyper-temporal Envisat ASAR ScanSAR backscatter data", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 7204-7207.
Abstract: Retrieval of forest growing stock volume (GSV) has been shown to be feasible with C-band backscatter data using hyper-temporal stacks. In this paper, we report on the generation of pan-boreal estimates of forest GSV representative for the year 2010 using Envisat ASAR ScanSAR backscatter measurements. More than 67,000 image strips acquired between October 2009 and February 2011 over the north American and the Eurasian continent have been multi-looked to 1 km pixel size, terrain geocoded to a pixel size of 0.01 degree, speckle filtered and corrected for slope-induced effects on the backscatter. Then, GSV has been retrieved with the BIOMASAR algorithm on a pixel-by-pixel basis. First results show the strong thematic accuracy of the GSV estimates due to the very large number of backscatter observations available and retained for retrieval. 2012 IEEE.
BibTeX:
@conference{Santoro20127204,
  author = {Santoro, M. and Schmullius, C. and Pathe, C. and Schwilk, J.},
  title = {Pan-boreal mapping of forest growing stock volume using hyper-temporal Envisat ASAR ScanSAR backscatter data},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {7204-7207},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873167000&doi=10.1109%2fIGARSS.2012.6352000&partnerID=40&md5=38cccb96ce02c79c33771d075299e8bb},
  doi = {10.1109/IGARSS.2012.6352000}
}
Santoro M and Wegmüller U (2012), "Multi-temporal SAR metrics applied to map water bodies", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 5230-5233.
Abstract: Multi-temporal synthetic aperture radar (SAR) metrics are investigated to assess their capability for mapping land cover types. The temporal variability and the minimum backscatter in a time series of Envisat Advanced SAR (ASAR) Wide Swath Mode (WSM) backscatter measurements present unique features over water surfaces with respect to other land cover types. A simple thresholding algorithm applied to these metrics is then presented to detect water bodies. Results from six study areas in Europe and Central Siberia show consistency of the behavior of the multi-temporal metrics over 'water' and 'land' areas regardless of the specific region. Water body detection accuracies are mostly above 90%, omissions occurring when a water body has a size similar to the pixel size of the SAR image. 2012 IEEE.
BibTeX:
@conference{Santoro20125230,
  author = {Santoro, M. and Wegmüller, U.},
  title = {Multi-temporal SAR metrics applied to map water bodies},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {5230-5233},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873136700&doi=10.1109%2fIGARSS.2012.6352430&partnerID=40&md5=019d57c62dd13bab2aedc84c4839c3e6},
  doi = {10.1109/IGARSS.2012.6352430}
}
Schafer M, Zwinger T, Christoffersen P, Gillet-Chaulet F, Laakso K, Pettersson R, Pohjola V, Strozzi T and Moore J (2012), "Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard", Cryosphere. Vol. 6(4), pp. 771-783.
Abstract: The dynamics of Vestfonna ice cap (Svalbard) are dominated by fast-flowing outlet glaciers. Its mass balance is poorly known and affected dynamically by these fast-flowing outlet glaciers. Hence, it is a challenging target for ice flow modeling. Precise knowledge of the basal conditions and implementation of a good sliding law are crucial for the modeling of this ice cap. Here we use the full-Stokes finite element code Elmer/Ice to model the 3-D flow over the whole ice cap. We use a Robin inverse method to infer the basal friction from the surface velocities observed in 1995. Our results illustrate the importance of the basal friction parameter in reproducing observed velocity fields. We also show the importance of having variable basal friction as given by the inverse method to reproduce the velocity fields of each outlet glacier-a simple parametrization of basal friction cannot give realistic velocities in a forward model. We study the robustness and sensitivity of this method with respect to different parameters (mesh characteristics, ice temperature, errors in topographic and velocity data). The uncertainty in the observational parameters and input data proved to be sufficiently small as not to adversely affect the fidelity of the model. 2012 Author(s).
BibTeX:
@article{Schafer2012771,
  author = {Schafer, M. and Zwinger, T. and Christoffersen, P. and Gillet-Chaulet, F. and Laakso, K. and Pettersson, R. and Pohjola, V.A. and Strozzi, T. and Moore, J.C.},
  title = {Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard},
  journal = {Cryosphere},
  year = {2012},
  volume = {6},
  number = {4},
  pages = {771-783},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867469539&doi=10.5194%2ftc-6-771-2012&partnerID=40&md5=1169257fa42e53a38cf26ae24f438ed7},
  doi = {10.5194/tc-6-771-2012}
}
Schwank M, Wigneron J-P, López-Baeza E, Volksch I, Matzler C and Kerr Y (2012), "L-band radiative properties of vine vegetation at the MELBEX III SMOS cal/val site", IEEE Transactions on Geoscience and Remote Sensing. Vol. 50(5 PART 1), pp. 1587-1601.
Abstract: Radiative properties at 1.4 GHz of vine vegetation are investigated by measuring brightness temperatures with the ETH L-band Radiometer II (ELBARA II) operated on a tower at the Mediterranean Ecosystem L-band Characterisation Experiment III (MELBEX III) field site in Spain. To this aim, experiments with and without a reflecting foil placed under the vines were performed for the vegetation winter and summer states, respectively, to provide prevailingly information on vegetation transmissivities. The resulting parameters, which can be considered as ground truth for the MELBEX III vineyard, were retrieved from brightness temperature at horizontal and vertical polarization measured at observation angles between 30° and 60°. These MELBEX III ground-truth values are representative for the Mediterranean Soil Moisture and Ocean Salinity (SMOS) Valencia Anchor Station (VAS) and therefore valuable for the corresponding calibration and validation activities over the VAS site. Likewise, quantifying the uncertainties of the measured brightness temperatures was also important, particularly as several equivalent ELBARA II instruments are currently operative in ongoing SMOS-related field campaigns. 2012 IEEE.
BibTeX:
@article{Schwank20121587,
  author = {Schwank, M. and Wigneron, J.-P. and López-Baeza, E. and Volksch, I. and Matzler, C. and Kerr, Y.H.},
  title = {L-band radiative properties of vine vegetation at the MELBEX III SMOS cal/val site},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2012},
  volume = {50},
  number = {5 PART 1},
  pages = {1587-1601},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860313055&doi=10.1109%2fTGRS.2012.2184126&partnerID=40&md5=0a7950b1af64b0fae582a57b0e65f8f1},
  doi = {10.1109/TGRS.2012.2184126}
}
Strozzi T, Wegmüller U, Werner C and Kos A (2012), "TerraSAR-X interferometry for surface deformation monitoring on periglacial area", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 5214-5217.
Abstract: Arctic and mountainous periglacial areas are subject to intense freezing cycles and characterized by remarkable surface displacement. We used TerraSAR-X interferometry to analyze the seasonal surface displacement on two regions in Alaska and Switzerland. In both cases, TerraSAR-X interferograms with an 11 days time interval are computed in series in order to maximize coherence. Seasonal subsidence maps highlight surface displacements of several centimeters while time-series show non-linear behaviors of the movements. 2012 IEEE.
BibTeX:
@conference{Strozzi20125214,
  author = {Strozzi, T. and Wegmüller, U. and Werner, C. and Kos, A.},
  title = {TerraSAR-X interferometry for surface deformation monitoring on periglacial area},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {5214-5217},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873145915&doi=10.1109%2fIGARSS.2012.6352434&partnerID=40&md5=0c3cf832880966459d96c35b523d3217},
  doi = {10.1109/IGARSS.2012.6352434}
}
Strozzi T, Werner C, Wiesmann A and Wegmüller U (2012), "Topography mapping with a portable real-aperture radar interferometer", IEEE Geoscience and Remote Sensing Letters. Vol. 9(2), pp. 277-281.
Abstract: In this letter, the requirements to derive topography from a portable terrestrial radar interferometer are introduced, the instrument design and the relationship between interferometric phase shift and surface topography are explained, and two examples of topographic maps from measurements at the Rhone glacier and Grabengufer rock glacier in Switzerland are presented. In the first case, an external digital elevation model was used to assess the error of topography mapping with the portable radar interferometer and to analyze ice surface changes of the glacier in the last 14 years. We found that the height error standard deviation is about 3 m within a distance of 2 km from the sensor and observed massive thinning of the Rhone glacier. In the second case, we used the terrestrial radar interferometer in order to measure the height difference between August 2009 and March 2010 over the rock glacier as a consequence of its destabilization. 2006 IEEE.
BibTeX:
@article{Strozzi2012277,
  author = {Strozzi, T. and Werner, C. and Wiesmann, A. and Wegmüller, U.},
  title = {Topography mapping with a portable real-aperture radar interferometer},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  year = {2012},
  volume = {9},
  number = {2},
  pages = {277-281},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84856955434&doi=10.1109%2fLGRS.2011.2166751&partnerID=40&md5=45cbdeada90f9057faef265761562c50},
  doi = {10.1109/LGRS.2011.2166751}
}
Strozzi T, Wiesmann A, Kaab A, Joshi S and Mool P (2012), "Glacial lake mapping with very high resolution satellite SAR data", Natural Hazards and Earth System Science. Vol. 12(8), pp. 2487-2498.
Abstract: Floods resulting from the outbursts of glacial lakes are among the most far-reaching disasters in high mountain regions. Glacial lakes are typically located in remote areas and space-borne remote sensing data are an important source of information about the occurrence and development of such lakes. Here we show that very high resolution satellite Synthetic Aperture Radar (SAR) data can be employed for reliably mapping glacial lakes. Results in the Alps, Pamir and Himalaya using TerraSAR-X and Radarsat-2 data are discussed in comparison to in-situ information, and high-resolution satellite optical and radar imagery. The performance of the satellite SAR data is best during the snow- and ice-free season. In the broader perspective of hazard management, the detection of glacial lakes and the monitoring of their changes from very high-resolution satellite SAR intensity images contributes to the initial assessment of hazards related to glacial lakes, but a more integrated, multi-level approach needs also to include other relevant information such as glacier outlines and outline changes or the identification of unstable slopes above the lake and the surrounding area, information types to which SAR analysis techniques can also contribute. Author(s) 2012.
BibTeX:
@article{Strozzi20122487,
  author = {Strozzi, T. and Wiesmann, A. and Kaab, A. and Joshi, S. and Mool, P.},
  title = {Glacial lake mapping with very high resolution satellite SAR data},
  journal = {Natural Hazards and Earth System Science},
  year = {2012},
  volume = {12},
  number = {8},
  pages = {2487-2498},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865241098&doi=10.5194%2fnhess-12-2487-2012&partnerID=40&md5=242c774c9f053872d54662f2b525de07},
  doi = {10.5194/nhess-12-2487-2012}
}
Teatini P, Tosi L and Strozzi T (2012), "Comment on "Recent subsidence of the Venice Lagoon from continuous GPS and interferometric synthetic aperture radar" by Y. Bock, S. Wdowinski, A. Ferretti, F. Novali, and A. Fumagalli", Geochemistry, Geophysics, Geosystems. Vol. 13(1) Blackwell Publishing Ltd.
BibTeX:
@article{Teatini2012,
  author = {Teatini, P. and Tosi, L. and Strozzi, T.},
  title = {Comment on "Recent subsidence of the Venice Lagoon from continuous GPS and interferometric synthetic aperture radar" by Y. Bock, S. Wdowinski, A. Ferretti, F. Novali, and A. Fumagalli},
  journal = {Geochemistry, Geophysics, Geosystems},
  publisher = {Blackwell Publishing Ltd},
  year = {2012},
  volume = {13},
  number = {1},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864571427&doi=10.1029%2f2012GC004191&partnerID=40&md5=0ab9855b2d02f407d3815461e52b1a89},
  doi = {10.1029/2012GC004191}
}
Teatini P, Tosi L, Strozzi T, Carbognin L, Cecconi G, Rosselli R and Libardo S (2012), "Resolving land subsidence within the Venice Lagoon by persistent scatterer SAR interferometry", Physics and Chemistry of the Earth. Vol. 40-41, pp. 72-79.
Abstract: Land subsidence is a severe geologic hazard threatening the lowlying transitional coastal areas worldwide. Monitoring land subsidence has been significantly improved over the last decade by space borne earth observation techniques based on Synthetic Aperture Radar (SAR) interferometry. Within the INLET Project, funded by Magistrato alle Acque di Venezia - Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN), we use Interferometric Point Target Analysis (IPTA) to characterize the ground displacements within the Venice Lagoon. IPTA measures the movement of backscattering point targets (PTs) at the ground surface that persistently reflect radar signals emitted by the SAR system at different passes. For this study 80 ERS-1/2 and 44 ENVISAT SAR scenes recorded from 1992 to 2005 and from 2003 to 2007, respectively, have been processed. Highly reliable displacement measurements have been detected for thousands of PTs located on the lagoon margins, along the littorals, in major and small islands, and on single structures scattered within the lagoon. On the average, land subsidence ranges from less than 1. mm/year to 5. mm/year, with some PTs that exhibit values also larger than 10. mm/year depending on both the local geologic conditions and the anthropic activities. A network of a few tens of artificial square trihedral corner reflectors (TCRs) has been established before summer 2007 in order to monitor land subsidence in the inner lagoon areas where " natural" reflectors completely lack (e.g., on the salt marshes). The first interferometric results on the TCRs appear very promising. 2010 Elsevier Ltd.
BibTeX:
@article{Teatini201272,
  author = {Teatini, P. and Tosi, L. and Strozzi, T. and Carbognin, L. and Cecconi, G. and Rosselli, R. and Libardo, S.},
  title = {Resolving land subsidence within the Venice Lagoon by persistent scatterer SAR interferometry},
  journal = {Physics and Chemistry of the Earth},
  year = {2012},
  volume = {40-41},
  pages = {72-79},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84858804914&doi=10.1016%2fj.pce.2010.01.002&partnerID=40&md5=5a1fb223f4333ffa771cc04dcf94cbe6},
  doi = {10.1016/j.pce.2010.01.002}
}
Tosi L, Strozzi T and Teatini P (2012), "Cosmo-skymed versus TerraSAR-X -based interferometry for monitoring the mose settlements at the Venice lagoon inlets", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 2837-2840.
Abstract: The modern approach of studying ground movements is aimed at distinguishing regional land subsidence and local consolidation processes, as well as long- and short- term displacements. With a very-high resolution images and a repeatability acquisitions never available in the past the new generation of SAR satellites provides helps to reach these achievements. In this work we compare the capability of Cosmo-SkyMed and TerraSAR-X for detecting the displacement of jetties, breakwaters, locks, and an artificial island which are under construction in the Venice lagoon inlets, Italy, as part of the anti-flood project MOSE Cosmo-SkyMed and TerraSAR-X have been also used to provide an updated quantification of the subsidence rates of the Venice and Chioggia historical centers. 2012 IEEE.
BibTeX:
@conference{Tosi20122837,
  author = {Tosi, L. and Strozzi, T. and Teatini, P.},
  title = {Cosmo-skymed versus TerraSAR-X -based interferometry for monitoring the mose settlements at the Venice lagoon inlets},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {2837-2840},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873151016&doi=10.1109%2fIGARSS.2012.6350841&partnerID=40&md5=b984dc7659ffb7cccbc4bc997a16272c},
  doi = {10.1109/IGARSS.2012.6350841}
}
Tosi L, Teatini P, Bincoletto L, Simonini P and Strozzi T (2012), "Integrating Geotechnical and Interferometric SAR Measurements for Secondary Compressibility Characterization of Coastal Soils", Surveys in Geophysics. Vol. 33(5), pp. 907-926.
Abstract: Persistent scatterer interferometry (PSI) provides a new perspective to monitor the movements of coastal structures due to long-term consolidation using satellite-borne remote sensors. The method has the advantages of detecting the displacements at a very high spatial (from 1 to a few meters) and temporal (from 10 to 30 days) resolution. Cost-effective monitoring of complex and large (some kilometer long) structures can be done over long time (up to 10 years) intervals and at large scales (tens times tens km 2) of investigation. Here, these measurements are integrated with geotechnical, site-specific measurements to characterize in a unique framework the long-term compressibility of coastal soils over large areas. The approach is tested on the 60-km-long coastland of the Venice Lagoon, Italy. An accurate quantification of the movements of coastal infrastructures at the Venice coastland is carried out by PSI using ENVISAT ASAR and TerraSAR-X images acquired from April 2003 to December 2009 and from March 2008 to January 2009, respectively. Several nearshore and offshore structures were constructed over the decades to protect Venice and its coastal environment from sea storms and high tides. Long jetties were built at the lagoon inlets since the end of the 18th century, significantly reinforced between 1994 and 1997, and finally reshaped since 2003 in the framework of the MOSE construction (i. e., the project of mobile barriers for the temporarily closure of the lagoon to the sea). The measured displacements range from a few mm/year for the structures older than 10 years to 50-70 mm/year for those realized a few years ago. The PSI measurements are combined with the outcome of a detailed geomechanical characterization of the lagoon subsoil obtained by a field-scale experiment started at the end of 2002 and monitored to 2008. The use of the stress-strain properties derived from the trial embankment and the actual lithostratigraphy below the coastal structures, which is available from several piezocone profiles and boreholes, allows for the computation of secondary compression (consolidation) rates that match very well the PSI-derived movements. The results provide important information on the potential of using PSI to characterizing geotechnical properties (magnitude and distribution) of coastal deposits, as well as to estimate the expected time-dependent geomechanical response of coastal structures or other large constructions. 2012 Springer Science+Business Media B.V.
BibTeX:
@article{Tosi2012907,
  author = {Tosi, L. and Teatini, P. and Bincoletto, L. and Simonini, P. and Strozzi, T.},
  title = {Integrating Geotechnical and Interferometric SAR Measurements for Secondary Compressibility Characterization of Coastal Soils},
  journal = {Surveys in Geophysics},
  year = {2012},
  volume = {33},
  number = {5},
  pages = {907-926},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864307146&doi=10.1007%2fs10712-012-9186-y&partnerID=40&md5=d5cf6a85974ae7deb914a4bbd5fdea50},
  doi = {10.1007/s10712-012-9186-y}
}
Voytenko D, Dixon T, Werner C, Gourmelen N, Howat I, Tinder P and Hooper A (2012), "Monitoring a glacier in southeastern Iceland with the portable Terrestrial Radar Interferometer", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3230-3232.
Abstract: Terrestrial Radar Interferometry (TRI) has several advantages for measuring glacier velocity. These ground-based systems alleviate problems associated with the long revisit times of satellites, and provide higher spatial sampling compared to GPS-based approaches. TRI is the technique of choice for rapidly moving glaciers, especially their terminal zones, which tend to exhibit high spatial and temporal variability. In this study, we use the Gamma Portable Radar Interferometer (GPRI) to measure the velocity of Breidamerkurjokull, a marine-terminating outlet glacier on the southeastern coast of Iceland, and compare it to TerraSAR-X data taken shortly after. We document significant temporal and spatial variability of ice velocity within 800 meters of the calving front. 2012 IEEE.
BibTeX:
@conference{Voytenko20123230,
  author = {Voytenko, D. and Dixon, T.H. and Werner, C. and Gourmelen, N. and Howat, I.M. and Tinder, P.C. and Hooper, A.},
  title = {Monitoring a glacier in southeastern Iceland with the portable Terrestrial Radar Interferometer},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3230-3232},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873181924&doi=10.1109%2fIGARSS.2012.6350736&partnerID=40&md5=30ac039b0bc533782f8b7359d50598e9},
  doi = {10.1109/IGARSS.2012.6350736}
}
Wegmüller U, Frey O and Werner C (2012), "Point density reduction in persistent scatterer interferometry", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2012-April, pp. 673-676. Institute of Electrical and Electronics Engineers Inc..
Abstract: Persistent Scatterer Interferometry (PSI) is widely used to determine ground deformation rates and histories. The data sets processed are increasing in size due to larger areas considered, higher resolution, and higher point densities. Working with lists of several million points and related networks reduces the computational efficiency. In this paper a method to adaptively reduce the size of the point list is presented. Considering the local point density and a point quality measure points are removed such that the density is significantly reduced in areas of very high density while maintaining the available density in areas of lower density. The main PSI processing is then done for the reduced point list. Later on the result obtained for the reduced list is expanded to the full point list. In several cases this methodology improves the processing efficiency significantly.
BibTeX:
@conference{Wegmuller2012673,
  author = {Wegmüller, U. and Frey, O. and Werner, C.},
  title = {Point density reduction in persistent scatterer interferometry},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2012},
  volume = {2012-April},
  pages = {673-676},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007454984&partnerID=40&md5=4df125ef75a9b65769eb57ec8d1ea407}
}
Wegmüller U, Strozzi T, Delaloye R and Raetzo H (2012), "Landslide mapping in Switzerland with ENVISAT ASAR", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1829-1832.
Abstract: In the frame of the IGARSS 2012 special session on ENVISAT the landslide mapping activities in Switzerland using ENVISAT ASAR data are presented. Between 2005 and 2010 the building up of a well suited archive over the Swiss Alps was realized through programming of all IS2 mode data during the snow free period. In recent years DINSAR and PSI based landslide inventory and monitoring products started to play an important role in the updating of hazard maps. 2012 IEEE.
BibTeX:
@conference{Wegmuller20121829,
  author = {Wegmüller, U. and Strozzi, T. and Delaloye, R. and Raetzo, H.},
  title = {Landslide mapping in Switzerland with ENVISAT ASAR},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {1829-1832},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873156068&doi=10.1109%2fIGARSS.2012.6351155&partnerID=40&md5=5bc5bf057e2965fead5be6ac3fe7d445},
  doi = {10.1109/IGARSS.2012.6351155}
}
Wegmüller U, Strozzi T and Werner C (2012), "Ionospheric path delay estimation using split-beam interferometry", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3631-3634.
Abstract: Azimuth spectrum band-pass filtering has been applied successfully for estimation of along-track ground displacement [1] as well as for other applications, such as the identification of directional scattering [2] and the coherence estimation for long-baseline pairs [3]. Particularly L-band split-beam interferograms have shown another phase component related to along-track variations in the ionospheric path delay. In our work we present methodologies to identify and quantify ionospheric path delays affecting an interferogram using the corresponding split-beam interferogram. 2012 IEEE.
BibTeX:
@conference{Wegmuller20123631,
  author = {Wegmüller, U. and Strozzi, T. and Werner, C.},
  title = {Ionospheric path delay estimation using split-beam interferometry},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2012},
  pages = {3631-3634},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873206223&doi=10.1109%2fIGARSS.2012.6350630&partnerID=40&md5=f90de27c5ad9ec680081a9b351c04d4f},
  doi = {10.1109/IGARSS.2012.6350630}
}
Wegmüller U, Strozzi T, Wiesmann A, Werner CL, Frey O, Caduff R and Kos A (2012), "Hangrutschungskartierung mittels Radar Interferometrie", Geomatik Schweiz. Vol. 110(9)
Abstract: Insbesondere durch die ERS-1, ERS-2 und ENVISAT ASAR Sensoren der Europäischen Raumfahrtsagentur ESA hat sich in den letzten 20 Jahren die SAR Interferometrie Methode sehr stark entwickelt. Ein wichtiger Anwendungsbereich ist die Kartierung von Geländebewegungen. Innerhalb der Schweiz wird die SAR Interferometrie Methodevor allem für die Kartierung von Hangrutschungen eingesetzt. Hangrutschungsinformation wird momentan für die Erstellung der Gefahrenhinweiskarten durch die Kantone benötigt. Angesichts einer wahrscheinlichen Zunahme der Hangrutschungs- undFelssturzgefahren durch die Klimaerwärmung und daraus resultierenden sekundärenVeränderungen, wie der Reduktion des Alpinen Permafrosts und des Gletscherrückzugs, kann mit einem zunehmenden Informationsbedarf gerechnet werden.
BibTeX:
@article{wegmullerStrozziWiesmannWernerFreyCaduffKosGEOMATIK2012DInSAR,
  author = {Wegmüller, Urs and Strozzi, Tazio and Wiesmann, Andreas and Werner, Charles L. and Frey, Othmar and Caduff, Rafael and Kos, Andrew},
  title = {Hangrutschungskartierung mittels Radar Interferometrie},
  journal = {Geomatik Schweiz},
  year = {2012},
  volume = {110},
  number = {9},
  url = {http://doi.org/10.5169/seals-309305}
}
Werner C, Wiesmann A, Strozzi T, Kos A, Caduff R and Wegmüller U (2012), "The GPRI multi-mode differential interferometric radar for ground-based observations", In Proc. European Conf. Synthetic Aperture Radar. Vol. 2012-April, pp. 304-307. Institute of Electrical and Electronics Engineers Inc..
Abstract: We describe the Gamma Portable Radar Interferometer (GPRI), an instrument designed to perform ground-based radar interferometry to measure surface deformation with an accuracy > 0.2 mm and generate digital elevation models (DEMs). Ground-based interferometric observations are complementary to spaceborne or airborne SAR based measurements because they can be acquired continuously in order to track rapid deformation and mitigate the effects of temporal decorrelation and atmospheric phase variability. Results from test cases are shown including the Aletsch glacier, Aletschwald, and Konthaus bridge in Bern.
BibTeX:
@conference{Werner2012304,
  author = {Werner, C. and Wiesmann, A. and Strozzi, T. and Kos, A. and Caduff, R. and Wegmüller, U.},
  title = {The GPRI multi-mode differential interferometric radar for ground-based observations},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2012},
  volume = {2012-April},
  pages = {304-307},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009715660&partnerID=40&md5=31ab22f41de461eea2cac471fce1392e}
}
Wigneron J-P, Schwank M, Baeza E, Kerr Y, Novello N, Millan C, Moisy C, Richaume P, Mialon A, Al Bitar A, Cabot F, Lawrence H, Guyon D, Calvet J-C, Grant J, Casal T, de Rosnay P, Saleh K, Mahmoodi A, Delwart S and Mecklenburg S (2012), "First evaluation of the simultaneous SMOS and ELBARA-II observations in the Mediterranean region", Remote Sensing of Environment. Vol. 124, pp. 26-37.
Abstract: The SMOS (Soil Moisture and Ocean Salinity) mission was launched on November 2, 2009. Over the land surfaces, simultaneous retrievals of surface soil moisture (SM) and vegetation characteristics made from the multi-angular and dual polarization SMOS observations are now available from Level-2 (L2) products delivered by the European Space Agency (ESA). Therefore, first analyses evaluating the SMOS observations in terms of Brightness Temperatures (TB) and L2 products (SM and vegetation optical depth TAU) can be carried out over several calibration/validation (cal/val) sites selected by ESA over all continents. This study is based on SMOS observations and in situ measurements carried out in 2010 over one of the main SMOS cal/val sites in Europe: the VAS (Valencia Anchor Station) site in the region of Utiel-Requena, close to Valencia, Spain. The main vegetation types in the region are vineyards, orchards and natural Mediterranean vegetation. The SMOS observations were analyzed in conjunction with those carried out by the L-band ELBARA-II radiometer over a vineyard which is considered as representative of the main land use of the VAS site. Time series of TB and retrievals of SM and TAU based on both the SMOS (L2 products) and the ELBARA-II observations were compared and evaluated against in situ measurements. A good agreement was found between the time variations in TB and in the retrieved SM values computed over the site from the SMOS and ELBARA-II observations (the determination coefficient R 2 was &gt;0.88 for the TB values and R 2&gt;0.64 for the retrieved SM values). However, it was found that the SMOS L2 SM products underestimated the SM values retrieved from ELBARA-II by  0.2m 3/m 3. It is likely this offset can be partially explained by differences between the observed scenes: while the ELBARA-II footprint includes a single vineyard, the heterogeneous SMOS footprint includes not only a large number of vineyards but also a natural Mediterranean vegetation with persistent leaves overlaying rocky soils. The time variations in TAU retrieved from the ELBARA-II observations were found to be closely related to those of the NDVI (Normalized Difference Vegetation Index) vegetation index obtained from MODIS (Moderate Resolution Imaging Spectroradiometer) (R 2=0.61) and revealed the vegetation cycle over the year. Conversely, the time variations in the SMOS Level-2 TAU product did not reveal any trends in relation to the vegetation development over the site. 2012 Elsevier Inc.
BibTeX:
@article{Wigneron201226,
  author = {Wigneron, J.-P. and Schwank, M. and Baeza, E.L. and Kerr, Y. and Novello, N. and Millan, C. and Moisy, C. and Richaume, P. and Mialon, A. and Al Bitar, A. and Cabot, F. and Lawrence, H. and Guyon, D. and Calvet, J.-C. and Grant, J.P. and Casal, T. and de Rosnay, P. and Saleh, K. and Mahmoodi, A. and Delwart, S. and Mecklenburg, S.},
  title = {First evaluation of the simultaneous SMOS and ELBARA-II observations in the Mediterranean region},
  journal = {Remote Sensing of Environment},
  year = {2012},
  volume = {124},
  pages = {26-37},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861333665&doi=10.1016%2fj.rse.2012.04.014&partnerID=40&md5=76ead5b0f40e4ea23acfaac572a3543f},
  doi = {10.1016/j.rse.2012.04.014}
}
Brocard E, Schneebeli M and Matzler C (2011), "Detection of cirrus clouds using infrared radiometry", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(2), pp. 595-602.
Abstract: The detection of low-level clouds from ground-based infrared (IR) radiometry is usually based on the IR brightness temperature (IRBT) contrast between the warm clouds and the cold clear-sky background. This method works as long as the brightness temperature contrast subsists. It is not the case for cirrus clouds, which are usually optically thin and exhibit a low brightness temperature, comparable to that of clear sky in similar atmospheric conditions. In this paper, we propose a detection scheme to discriminate between clear sky and cirrus sky based on the fluctuations of the IRBT rather than on the absolute IRBT values. For this, we use the detrended fluctuation analysis (DFA) method on IRBT data when no liquid clouds were present. We compute the exponent α for nine IRBT time series covering clear- and cirrus-sky situations. We find that, for the fluctuation range of 1-5 min, α ≃ 0.1 for clear sky, α ≃ 0.5 for stratiform cirrus layers, and α ≃ 1 for broken cirrus layers. We suggest a threshold value of α = 0.25 for the discrimination between clear sky and cirrus sky. We also examine the relationship between DFA and the classical spectral analysis and find that spectral analysis could be an alternative to the DFA method in detecting the presence of cirrus clouds. 2006 IEEE.
BibTeX:
@article{Brocard2011595,
  author = {Brocard, E. and Schneebeli, M. and Matzler, C.},
  title = {Detection of cirrus clouds using infrared radiometry},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {2},
  pages = {595-602},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79151471813&doi=10.1109%2fTGRS.2010.2063033&partnerID=40&md5=e56cde8cf5b983dc9eb1a3ed8aedda86},
  doi = {10.1109/TGRS.2010.2063033}
}
Cartus O, Santoro M, Schmullius C and Li Z (2011), "Large area forest stem volume mapping in the boreal zone using synergy of ERS-1/2 tandem coherence and MODIS vegetation continuous fields", Remote Sensing of Environment. Vol. 115(3), pp. 931-943.
Abstract: ERS-1/2 tandem coherence was reported to have high potential for the mapping of boreal forest stem volume (e.g. Santoro et al., 2002, 2007a; Wagner et al., 2003; Askne &amp; Santoro, 2005). Large-scale application of the data for forest stem volume mapping, however, is hindered by the variability of coherence with meteorological and environmental acquisition conditions. The traditional way of stem volume retrieval is based on the training of models, relating coherence to stem volume, with the aid of forest inventory data which is generally available for a few small test sites but not for large areas. In this paper a new approach is presented that allows model training using the MODIS Vegetation Continuous Fields canopy cover product (Hansen et al., 2003) without further need for ground data. A comparison of the new approach with the traditional regression-based and ground-data dependent model training is presented in this paper for a multi-seasonal ERS-1/2 tandem dataset covering several well known Central Siberian forest sites. As a test scenario for large-area application, the approach was applied to a multi-seasonal ERS-1/2 tandem dataset of 223 ERS-1 and ERS-2 image pairs covering Northeast China ( 1.5millionkm2) to map four stem volume classes (0-20, 20-50, 50-80, and &gt;80m3/ha). 2010 Elsevier Inc.
BibTeX:
@article{Cartus2011931,
  author = {Cartus, O. and Santoro, M. and Schmullius, C. and Li, Z.},
  title = {Large area forest stem volume mapping in the boreal zone using synergy of ERS-1/2 tandem coherence and MODIS vegetation continuous fields},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {3},
  pages = {931-943},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651428989&doi=10.1016%2fj.rse.2010.12.003&partnerID=40&md5=55f8d0c5d614938d64eafa0821870111},
  doi = {10.1016/j.rse.2010.12.003}
}
Casu F, Manconi A, Pepe A and Lanari R (2011), "Deformation time-series generation in areas characterized by large displacement dynamics: The SAR amplitude pixel-offset SBAS technique", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(7), pp. 2752-2763.
Abstract: We exploit the amplitude information of a sequence of synthetic aperture radar (SAR) images, acquired at different times, in order to generate displacement time-series in areas characterized by large and/or rapid deformation, the size of which is on the order of the image's pixel dimensions. We follow the same rationale of the Small BAseline Subset (SBAS) differential SAR interferometry (DInSAR) approach, by coupling the available SAR images into pairs characterized by a small separation between the acquisition orbits. We exploit the amplitudes of the selected image pairs in order to calculate the relative across-track (range) and along-track (azimuth) pixel-offsets (PO). Finally, we apply the SBAS inversion strategy to retrieve the range and azimuth displacement time-series. This approach, referred to as pixel-offset (PO-) SBAS technique, has been applied to a set of 25 ENVISAT SAR observations of the Sierra Negra caldera, Galpagos Islands, spanning the 20032007 time interval. The retrieved deformation time-series show the capability of the technique to detect and measure the large displacements affecting the inner part of the caldera that, in correspondence to the October 2005 eruption, reached several meters. Moreover, by comparing the PO-SBAS results to continuous GPS measurements, we estimate that the accuracy of the PO-SBAS time-series is on the order of 1/30th of a pixel for both range and azimuth directions. 2011 IEEE.
BibTeX:
@article{Casu20112752,
  author = {Casu, F. and Manconi, A. and Pepe, A. and Lanari, R.},
  title = {Deformation time-series generation in areas characterized by large displacement dynamics: The SAR amplitude pixel-offset SBAS technique},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {7},
  pages = {2752-2763},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79959733508&doi=10.1109%2fTGRS.2010.2104325&partnerID=40&md5=d25eceab52c1f3bde54992e7ae251be7},
  doi = {10.1109/TGRS.2010.2104325}
}
Dimitrov M, Vanderborght J, Jadoon K, Schwank M, Weihermueller L and Vereecken H (2011), "Closed loop brightness temperature data inversion for the retrieval of soil hydraulic properties", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1219-1222.
Abstract: We combined the radiative transfer approach to simulate L-band brightness temperatures at 1.4 GHz with a hydrological simulator (HYDRUS 1D) and a global optimization routine SCE-UA to estimate the Mualem van Genuchten (MVG) soil hydraulic parameters from time-lapse L-band brightness temperatures and in situ soil moisture measurements at different depths. The measurements were collected from a bare soil plot, prepared after ploughing. First, we briefly described the coupled inversion procedure and compared the results with measured brightness temperatures and in-situ soil moisture data. Second, estimated soil hydraulic parameters were compared with laboratory derived ones. The results suggest that the proposed method is promising for the effective characterization of the soil hydraulic properties and the determination of soil moisture within the top soil layer. 2011 IEEE.
BibTeX:
@conference{Dimitrov20111219,
  author = {Dimitrov, M. and Vanderborght, J. and Jadoon, K.Z. and Schwank, M. and Weihermueller, L. and Vereecken, H.},
  title = {Closed loop brightness temperature data inversion for the retrieval of soil hydraulic properties},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2011},
  pages = {1219-1222},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80955150909&doi=10.1109%2fIGARSS.2011.6049418&partnerID=40&md5=7c2cd7743b1d58523faadaf4bd3c93a2},
  doi = {10.1109/IGARSS.2011.6049418}
}
Frey O and Meier E (2011), "3-D time-domain SAR imaging of a forest using airborne multibaseline data at L-and P-bands", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(10 PART 1), pp. 3660-3664.
Abstract: In this paper, a time-domain back-projection based tomographic processing approach to a 3-D reconstruction grid is detailed, with the focusing in the third dimension being either modified versions of multilook standard beamforming, robust Capon beamforming, or multiple signal classification. The novel feature of the proposed approach compared to previous synthetic aperture radar (SAR) tomography approaches is that it allows for an approximation-free height-dependent calculation of the sample covariance matrix by exploiting the azimuth-focused data on the 3-D reconstruction grid. The method is applied to experimental multibaseline quad-pol SAR data at L-and P-bands acquired by German Aerospace Center's (DLR) E-SAR sensor: Tomographic images of a partially forested area, including a 3-D voxel plot that visualizes the very high level of detail of the tomographic image, are shown, and an analysis of the focusing performance is given for the full as well as reduced synthetic aperture in the normal direction. 2011 IEEE.
BibTeX:
@article{Frey20113660,
  author = {Frey, O. and Meier, E.},
  title = {3-D time-domain SAR imaging of a forest using airborne multibaseline data at L-and P-bands},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {10 PART 1},
  pages = {3660-3664},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053575857&doi=10.1109%2fTGRS.2011.2128875&partnerID=40&md5=5cca2b5db6982d3e938f2ae090b9fff2},
  doi = {10.1109/TGRS.2011.2128875}
}
Frey O and Meier E (2011), "Analyzing tomographic SAR data of a forest with respect to frequency, polarization, and focusing technique", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(10), pp. 3648-3659.
Abstract: Forest canopies are semitransparent to microwaves at both L-and P-bands. Thus, a number of scattering sources and different types of scattering mechanisms may contribute to a single range cell of a synthetic aperture radar (SAR) image. By appropriately combining the SAR data of multiple parallel flight paths, a large 2-D aperture is synthesized, which allows for tomographic imaging of the 3-D structure of such semitransparent media and the underlying ground. A separate paper deals with the actual tomographic imaging part that leads to the 3-D data cube. In particular, three focusing techniques are described and analyzed: multilook beamforming, robust Capon beamforming, and multiple signal classification beamforming. In this paper, the resulting data products obtained by tomographically focusing two airborne multibaseline SAR data sets of a partially forested area, one at L-band and another at P-band, are subject to a detailed analysis with respect to the location and the type of backscattering sources. In particular, the following aspects are investigated: 1) The forest structure, as obtained from the vertical profiles of intensities at sample plot locations within the forest, is compared to the height distribution of the top of the forest canopy, as derived from airborne laser scanning data, and profiles are presented for all polarimetric channels and focusing techniques, as well as at both frequencies; 2) the type and location of scattering mechanisms are analyzed as functions of height for the two frequencies, namely, L-and P-bands, and using the polarimetric channels, as well as the Pauli and Cloude-Pottier decompositions thereof; and 3) the accuracy of the ground elevation estimation obtained from the different focusing techniques and the two frequencies is assessed with the help of a lidar-derived digital elevation model. 2011 IEEE.
BibTeX:
@article{Frey20113648,
  author = {Frey, Othmar and Meier, E.},
  title = {Analyzing tomographic SAR data of a forest with respect to frequency, polarization, and focusing technique},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {10},
  pages = {3648-3659},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053571947&doi=10.1109%2fTGRS.2011.2125972&partnerID=40&md5=235dc7e32ff82cd05f01e984be26d31d},
  doi = {10.1109/TGRS.2011.2125972}
}
Frey O and Meier E (2011), "Characterizing the Backscattering Properties of a Forest by Polarimetric SAR Tomography at L- and P-Bands", In Proc. PolInSAR, 5th Int. Workshop on Science and Applications of SAR Polarimetry and Polarimetric Interferometry. Frascati, Italy, January, 2011.
BibTeX:
@inproceedings{freyMeierPolInsAR2011:Tomo,
  author = {Othmar Frey and Erich Meier},
  title = {Characterizing the Backscattering Properties of a Forest by Polarimetric SAR Tomography at L- and P-Bands},
  booktitle = {Proc. PolInSAR, 5th Int. Workshop on Science and Applications of SAR Polarimetry and Polarimetric Interferometry},
  year = {2011}
}
Frey O, Meier E and Hajnsek I (2011), "On the sensitivity of measured backscattering properties to variations of incidence angle and baselines in tomographic SAR data", In 2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011. , pp. 571-574.
Abstract: SAR tomography at L- and P-bands reveals 3-D structural information of forested areas. A drawback, however, are the large number of samples, i.e. overflights, typically used for such configurations. Based on two fully-polarimetric tomographic SAR data sets, at L- and P-bands, we analyze the sensitivity of backscattering from a forest volume as measured by means of SAR tomography with respect to (1) a reduction of the total baseline by subsequently reducing the number of baselines, and (2), with respect to a variation of the incidence angle. In this paper, an excerpt of this sensitivity analysis is presented and discussed. 2011 KIEES.
BibTeX:
@conference{Frey2011571,
  author = {Frey, O. and Meier, E. and Hajnsek, I.},
  title = {On the sensitivity of measured backscattering properties to variations of incidence angle and baselines in tomographic SAR data},
  booktitle = {2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011},
  year = {2011},
  pages = {571-574},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-83755182710&partnerID=40&md5=672b6aa8ad16d98dede786a2b84dd7df}
}
Graham E, Sarazin M and Matzler C (2011), "Using re-analysis model data to analyse climate trends related to the astroclimatology of Paranal and La Silla", In Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias. Vol. 41, pp. 12-15.
Abstract: This paper consists of a summary of the results of two separate research exercises. In the first part, the relationship between astronomical night-time viewing statistics (Seeing and Photometric Night Fraction) from ESO Paranal-La Silla observatories and thirty-five ERA-40 and NCEP-NCEP re-analyses variables (available with the FriOWL software) were examined for correlation, using data from the re-analysis model gridpoint closest to the two observatories. The results confirm that the photometric night fraction datasets of both observatories are better described than are the seeing datasets. The strongest relationships are found at La Silla due to its more southerly, baroclinic location. Interestingly, the NOAA outgoing longwave radiation (OLR) dataset performs equally well, or better than its equivalent ERA40 re-analyses cloud cover dataset. In second part of this study, the FriOWL tool was used in an analysis of the climatology of northern Chile region, to help determine the cause of a deterioration in astronomical seeing conditions at Paranal from 1998 onwards. The results show that an exceptional increase in lOOOhPa geopotential height has occurred to the south-east of Paranal over the 1998-2007 period, when compared to the previous nine-year period. This increase is not replicated at the 700, 500 or 200 hPa levels, however. A shift south in the axis of near-surface geopotential heights from 21°S to 25-27°S has also occurred over the same period. Furthermore, there appears to be a link between phase shifts of the Interdecadal Pacific Oscillation, and atmospheric circulation anomalies over the Pacific region. 2011: Instituto de Astronomía, UNAM - Astronomical Site Testing Data in Chile Ed. M. Curé, A. Otárola, J. Marín, & M. Sarazin.
BibTeX:
@conference{Graham201112,
  author = {Graham, E. and Sarazin, M. and Matzler, C.},
  title = {Using re-analysis model data to analyse climate trends related to the astroclimatology of Paranal and La Silla},
  booktitle = {Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias},
  year = {2011},
  volume = {41},
  pages = {12-15},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878312608&partnerID=40&md5=c067dec3f4a34f8c41a97aca91a4afb8}
}
Grenerczy G and Wegmüller U (2011), "Persistent scatterer interferometry analysis of the embankment failure of a red mud reservoir using ENVISAT ASAR data", Natural Hazards. Vol. 59(2), pp. 1047-1053.
Abstract: On October 4, 2010, the embankment of No. 10 red mud-waste product during bauxite refining-reservoir of MAL Co. Ltd. alumina plant collapsed. Around 700 000 cubic meter of alkaline slurry with 11-13 pH value flooded three nearby settlements. Ten people were killed, 123 wounded, and about 350 houses were damaged or became uninhabitable in one of the biggest industrial and ecological catastrophe in modern history of Hungary. Synthetic aperture radar interferometry (InSAR) is the only geodetic technique that can reveal the past stability and motion history of the broken reservoir. We performed a persistent scatterer InSAR (PSI) analysis to contribute to the better understanding of the disaster. The key question we address in this study is whether there were signs prior to October 4th event which may have prognosticated the disaster. The PSI results could reveal if the dam was stable in the past without prior signs of the failure or there were definite indications of deformation before the collapse and proper monitoring of motions could have highlighted the risk and the disaster may have been prevented. This is a rare event and its PSI study is unique and may be critical in understanding it and helping to prevent other similar occurrences. 2011 Springer Science+Business Media B.V.
BibTeX:
@article{Grenerczy20111047,
  author = {Grenerczy, G. and Wegmüller, U.},
  title = {Persistent scatterer interferometry analysis of the embankment failure of a red mud reservoir using ENVISAT ASAR data},
  journal = {Natural Hazards},
  year = {2011},
  volume = {59},
  number = {2},
  pages = {1047-1053},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053563595&doi=10.1007%2fs11069-011-9816-6&partnerID=40&md5=e1e745dd74bb5eeb26ad5745d5c559cc},
  doi = {10.1007/s11069-011-9816-6}
}
Guglielmino F, Bignami C, Bonforte A, Briole P, Obrizzo F, Puglisi G, Stramondo S and Wegmüller U (2011), "Analysis of satellite and in situ ground deformation data integrated by the SISTEM approach: The April 3, 2010 earthquake along the Pernicana fault (Mt. Etna - Italy) case study", Earth and Planetary Science Letters. Vol. 312(3-4), pp. 327-336.
Abstract: Etna is known worldwide as one of the most studied and monitored active volcanoes. Flank instability along the eastern and southern portions of Mt. Etna has been observed and measured thanks to geodetic networks and InSAR data analysis. The spreading area is bordered to the north by the east-west Pernicana Fault System (PFS) whose dynamics is often linked with the eruptive activity, as recently observed during the 2002-2003 eruption. A seismic sequence occurred from April 2-3, 2010, along the PFS with very shallow (a few hundred meters) mainshocks of magnitude 4.3 and 3.6. Explosions and ash emissions at the summit craters followed this swarm culminating a few days later (April 7-8). Despite their small magnitude, the earthquakes caused damage and significant surface fracturing along the PFS. In order to investigate and measure the deformations in the near field of the earthquakes, the SISTEM integration approach has been exploited. The SISTEM enabled integrating geodetic in situ ground deformation measurements (GPS and leveling) with satellite interferometric measurements (ENVISAT and ALOS), in order to obtain high resolution 3D displacement maps, allowing to overcome the limitations of each technique and take advantage of the particular features of each of them. The integrated ground deformation field evidenced that the medium behave elastically. We inverted the SISTEM results using an optimization algorithm based on the Genetic Algorithm (GA) in order to model the kinematics of the PFS associated to seismic swarm; the results are in good agreement with the field evidence and improved the knowledge on the kinematics of the PFS and Mt. Etna's unstable flank. 2011 Elsevier B.V.
BibTeX:
@article{Guglielmino2011327,
  author = {Guglielmino, F. and Bignami, C. and Bonforte, A. and Briole, P. and Obrizzo, F. and Puglisi, G. and Stramondo, S. and Wegmüller, U.},
  title = {Analysis of satellite and in situ ground deformation data integrated by the SISTEM approach: The April 3, 2010 earthquake along the Pernicana fault (Mt. Etna - Italy) case study},
  journal = {Earth and Planetary Science Letters},
  year = {2011},
  volume = {312},
  number = {3-4},
  pages = {327-336},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-81255166168&doi=10.1016%2fj.epsl.2011.10.028&partnerID=40&md5=ded9f6748fdc31b40608f6d683cd0b78},
  doi = {10.1016/j.epsl.2011.10.028}
}
Hocke K, Kampfer N, Gerber C and Matzler C (2011), "A complete long-term series of integrated water vapour from ground-based microwave radiometers", International Journal of Remote Sensing. Vol. 32(3), pp. 751-765. Taylor and Francis Ltd..
Abstract: Integrated water vapour (IWV) is the vertical column density of atmospheric water vapour. IWV can be determined from microwave radiances measured by multi-channel radiometers on the ground or in space. Both quality and quantity of IWV measurements have rapidly increased during the past 10 to 20 years. Global maps and time series of IWV give evidence for a strong spatio-temporal variability of atmospheric water vapour, playing a key role in weather prediction and climate-change research. We analyse the relationships between microwave radiances and IWV using long-term observations of two radiometers at Bern, Switzerland. The first radiometer (Tropospheric Water Vapour Radiometer; TROWARA) measures 21 and 31 GHz radiances and permits the accurate retrieval of IWV. The long-term series of the TROWARA have some data gaps that possibly influence the trend analysis. On the other hand, the series of 142 GHz radiance of the second radiometer (Ground-based Millimeter-wave Ozone Spectrometer; GROMOS) are almost complete. The 142 GHz radiance is more affected by integrated cloud liquid water (ILW) than the 21 and 31 GHz radiances. The coincident radiometer data of GROMOS and TROWARA are utilized for exploration of the relationship between 142 GHz radiance, IWV and ILW. The IWV is calculated from the 142 GHz radiance of GROMOS when TROWARA data are not available. Thus, we can derive a complete series of IWV above Bern from 1994 to 2009. The combination of both series and the trend analysis are performed by means of multiple linear regression and bootstrapping. The observations indicate a positive trend up to +10% decade-1 of IWV in summer and a negative trend of about -15% decade-1 in winter. 2011 Taylor &amp; Francis.
BibTeX:
@article{Hocke2011751,
  author = {Hocke, K. and Kampfer, N. and Gerber, C. and Matzler, C.},
  title = {A complete long-term series of integrated water vapour from ground-based microwave radiometers},
  journal = {International Journal of Remote Sensing},
  publisher = {Taylor and Francis Ltd.},
  year = {2011},
  volume = {32},
  number = {3},
  pages = {751-765},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79952400280&doi=10.1080%2f01431161.2010.517792&partnerID=40&md5=c87e067eba743ff5010a8b0105a2520c},
  doi = {10.1080/01431161.2010.517792}
}
Jonard F, Weihermuller L, Jadoon K, Schwank M, Vereecken H and Lambot S (2011), "Mapping field-scale soil moisture with L-band radiometer and ground-penetrating radar over bare soil", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(8), pp. 2863-2875.
Abstract: Accurate estimates of surface soil moisture are essential in many research fields, including agriculture, hydrology, and meteorology. The objective of this study was to evaluate two remote-sensing methods for mapping the soil moisture of a bare soil, namely, L-band radiometry using brightness temperature and ground-penetrating radar (GPR) using surface reflection inversion. Invasive time-domain reflectometry (TDR) measurements were used as a reference. A field experiment was performed in which these three methods were used to map soil moisture after controlled heterogeneous irrigation that ensured a wide range of water content. The heterogeneous irrigation pattern was reasonably well reproduced by both remote-sensing techniques. However, significant differences in the absolute moisture values retrieved were observed. This discrepancy was attributed to different sensing depths and areas and different sensitivities to soil surface roughness. For GPR, the effect of roughness was excluded by operating at low frequencies (0.2-0.8 GHz) that were not sensitive to the field surface roughness. The root mean square (rms) error between soil moisture measured by GPR and TDR was 0.038 m3 · m-3. For the radiometer, the rms error decreased from 0.062 (horizontal polarization) and 0.054 (vertical polarization) to 0.020 m3 · m-3 (both polarizations) after accounting for roughness using an empirical model that required calibration with reference TDR measurements. Monte Carlo simulations showed that around 20% of the reference data were required to obtain a good roughness calibration for the entire field. It was concluded that relatively accurate measurements were possible with both methods, although accounting for surface roughness was essential for radiometry. 2011 IEEE.
BibTeX:
@article{Jonard20112863,
  author = {Jonard, F. and Weihermuller, L. and Jadoon, K.Z. and Schwank, M. and Vereecken, H. and Lambot, S.},
  title = {Mapping field-scale soil moisture with L-band radiometer and ground-penetrating radar over bare soil},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {8},
  pages = {2863-2875},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960907712&doi=10.1109%2fTGRS.2011.2114890&partnerID=40&md5=a30221b2cdbf4af873bee37cd14ecb66},
  doi = {10.1109/TGRS.2011.2114890}
}
Jonard F, Weihermuller L, Schwank M, Vereecken H and Lambot S (2011), "Soil moisture retrieval using L-band radiometer and ground-penetrating radar", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 3093-3096.
Abstract: The objective of this study was to evaluate two remote-sensing methods for mapping the surface soil moisture of a bare soil, namely L-band radiometry using brightness temperature and ground-penetrating radar (GPR) using surface reflection inversion. Invasive time-domain reflectometry (TDR) measurements were used as a reference. A field experiment was performed in which these three methods were used to map soil moisture after controlled heterogeneous irrigation that ensured a wide range of water content. The heterogeneous irrigation pattern was reasonably well reproduced by both remote-sensing techniques. For GPR, the effect of roughness was excluded by operating at low frequencies (0.2-0.8 GHz) that were not sensitive to the field surface roughness. For the radiometer, the effect of roughness was accounted for using an empirical model that required calibration with the reference TDR measurements. The root mean square (RMS) error between soil moisture measured by GPR and TDR was 0.038 m3 m- while the RMS error between radiometer (horizontal and vertical polarizations)- and TDR-derived soil water content was 0.020 m 3 m-3. These results suggest that both remote-sensing techniques are promising for field-scale mapping of surface soil moisture over bare soils. 2011 IEEE.
BibTeX:
@conference{Jonard20113093,
  author = {Jonard, F. and Weihermuller, L. and Schwank, M. and Vereecken, H. and Lambot, S.},
  title = {Soil moisture retrieval using L-band radiometer and ground-penetrating radar},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2011},
  pages = {3093-3096},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80955159758&doi=10.1109%2fIGARSS.2011.6049872&partnerID=40&md5=bbc4cceff16407eaf117b952941e5edd},
  doi = {10.1109/IGARSS.2011.6049872}
}
Lemmetyinen J, Pulliainen J, Arslan A, Kontu A, Rautiainen K, Vehvilainen J, Wiesmann A, Nagler T, Rott H, Davidson M, Schuettemeyer D and Kern M (2011), "Analysis of active and passive microwave observations from the NoSREx campaign", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 2737-2740.
Abstract: The acquisition of Snow Water Equivalent (SWE) at spatial resolutions higher than those of the present methods relying on inversion of coarse-scale passive microwave observations is a possible application for space-borne SAR imagery. The presented experimental campaign NoSREx (Nordic Snow Radar Experiment) was initiated to contribute to the knowledge of snowpack backscattering and emission properties, in particular, to help develop methods to retrieve SWE from high-resolution two-frequency SAR observations (at X and Ku band). Another objective was to provide data for studies exploring the synergistic use of active and passive microwave observations for monitoring of snow properties. The NoSREx campaign began in November 2009, and has recently concluded a second winter period of observations. 2011 IEEE.
BibTeX:
@conference{Lemmetyinen20112737,
  author = {Lemmetyinen, J. and Pulliainen, J. and Arslan, A. and Kontu, A. and Rautiainen, K. and Vehvilainen, J. and Wiesmann, A. and Nagler, T. and Rott, H. and Davidson, M. and Schuettemeyer, D. and Kern, M.},
  title = {Analysis of active and passive microwave observations from the NoSREx campaign},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2011},
  pages = {2737-2740},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80955139550&doi=10.1109%2fIGARSS.2011.6049780&partnerID=40&md5=30b209adc2c8c2271127e46ecaf18110},
  doi = {10.1109/IGARSS.2011.6049780}
}
Parde M, J.-P. W, Zribi M, Kerr Y, Fanise P, Calvet J-C, Albergel C, Albitar A, Cabot F, Demontoux F, Jacquette E, Lopez-Baeza E, Mialon A, Moisy C, Novello N, Richaume P, Saleh K, Schwank M, Waldteufel P, Zakharova E and Dechambre M (2011), "Retrievals of soil moisture and optical depth from CAROLS", In Progress in Electromagnetics Research Symposium. , pp. 80-84.
Abstract: We propose in this paper to evaluate a method to retrieve soil moisture (SM) and vegetation optical thickness, in areas of unknown roughness and unknown vegetation water content in view of operational applications, by using airborne Tb measurements acquired in South-West of France. Results are compared to in situ measurements, manual and automatic ones included in SMOSmania network, in the South-West of France.
BibTeX:
@conference{Parde201180,
  author = {Parde, M. and Wigneron J.-P. and Zribi, M. and Kerr, Y. and Fanise, P. and Calvet, J.-C. and Albergel, C. and Albitar, A. and Cabot, F. and Demontoux, F. and Jacquette, E. and Lopez-Baeza, E. and Mialon, A. and Moisy, C. and Novello, N. and Richaume, P. and Saleh, K. and Schwank, M. and Waldteufel, P. and Zakharova, E. and Dechambre, M.},
  title = {Retrievals of soil moisture and optical depth from CAROLS},
  booktitle = {Progress in Electromagnetics Research Symposium},
  year = {2011},
  pages = {80-84},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84055184129&partnerID=40&md5=d62ed9503f9179f1552cbabf09b6a774}
}
Pettersson R, Christoffersen P, Dowdeswell J, Pohjola V, Hubbard A and Strozzi T (2011), "Ice Thickness and Basal Conditions of Vestfonna Ice Cap, Eastern Svalbard", Geografiska Annaler, Series A: Physical Geography. Vol. 93(4), pp. 311-322.
Abstract: We combined ground-based pulsed radar data collected in 2008-2009 with airborne radio-echo sounding data acquired in 1983 and 1986 over Vestfonna ice cap, Svalbard. The airborne dataset mainly covers the fast-flowing outlet glaciers and the marginal zone, while the ground-based data explicitly cover the interior part of the ice cap. The data presented here are thus the first complete estimate of bed topography and ice thickness. The subglacial landscape undulates with elevations between -160 and +410m above sea level. The mean ice thickness is 186m and the total ice area and volume are 2402km2 and 442±0.6km3, respectively. This is a much smaller volume than those derived from empirical volume-area scaling relationships currently used to estimate regional-to-global glacier volumes. This difference may depend on local conditions for Vestfonna and emphasizes the need to include more volume observations in the derivations of volume-area scaling parameters. We also derive basal reflectivity as a proxy for thermal conditions at the bed. Basal reflectivity values suggest that fast-flowing outlet glaciers are underlain by temperate conditions. The geometric boundaries and basal conditions for Vestfonna will be critical additions to the development of numerical models of the ice cap and to the estimation of more accurate area-volume scaling parameters. The authors 2011. Geografiska Annaler: Series A, Physical Geography 2011 Swedish Society for Anthropology and Geography.
BibTeX:
@article{Pettersson2011311,
  author = {Pettersson, R. and Christoffersen, P. and Dowdeswell, J.A. and Pohjola, V.A. and Hubbard, A. and Strozzi, T.},
  title = {Ice Thickness and Basal Conditions of Vestfonna Ice Cap, Eastern Svalbard},
  journal = {Geografiska Annaler, Series A: Physical Geography},
  year = {2011},
  volume = {93},
  number = {4},
  pages = {311-322},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-83055166294&doi=10.1111%2fj.1468-0459.2011.00438.x&partnerID=40&md5=794a5de6ab77b19dca220e1054d8ae31},
  doi = {10.1111/j.1468-0459.2011.00438.x}
}
Pohjola V, Christoffersen P, Kolondra L, Moore J, Pettersson R, Schafer M, Strozzi T and Reijmer C (2011), "Spatial Distribution and Change in the Surface Ice-Velocity Field of Vestfonna Ice Cap, Nordaustlandet, Svalbard, 1995-2010 Using Geodetic and Satellite Interferometry Data", Geografiska Annaler, Series A: Physical Geography. Vol. 93(4), pp. 323-335.
Abstract: During 2007 we launched a geodetic campaign on the Svalbard ice cap Vestfonna in order to estimate the velocity field of the ice cap. This was done within the frame of the IPY project KINNVIKA. We present here the velocity measurements derived from our campaigns 2007-2010 and compare the geodetic measurements against InSAR velocity fields from satellite platforms from 1995/96 and 2008. We find the spatial distribution of ice speeds from the InSAR is in good agreement within the uncertainty limits with our geodetic measurements. We observe no clear indication of seasonal ice speed differences, but we find a speed-up of the outlet glacier Franklinbreen between the InSAR campaigns, and speculate the outlet is having a surge phase. The authors 2011. Geografiska Annaler: Series A, Physical Geography 2011 Swedish Society for Anthropology and Geography.
BibTeX:
@article{Pohjola2011323,
  author = {Pohjola, V.A. and Christoffersen, P. and Kolondra, L. and Moore, J.C. and Pettersson, R. and Schafer, M. and Strozzi, T. and Reijmer, C.H.},
  title = {Spatial Distribution and Change in the Surface Ice-Velocity Field of Vestfonna Ice Cap, Nordaustlandet, Svalbard, 1995-2010 Using Geodetic and Satellite Interferometry Data},
  journal = {Geografiska Annaler, Series A: Physical Geography},
  year = {2011},
  volume = {93},
  number = {4},
  pages = {323-335},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-83055169887&doi=10.1111%2fj.1468-0459.2011.00441.x&partnerID=40&md5=b6429873a51f16d1bc99d9598d2bc2bc},
  doi = {10.1111/j.1468-0459.2011.00441.x}
}
Riesen P, Strozzi T, Bauder A, Wiesmann A and Funk M (2011), "Short-term surface ice motion variations measured with a ground-based portable real aperture radar Interferometer", Journal of Glaciology. Vol. 57(201), pp. 53-60.
Abstract: We report measurements using a portable real aperture radar (Gamma Portable Radar Interferometer (GPRI)) for interferometric imaging of the surface ice motion on Gornergletscher, Switzerland, during the drainage of the adjacent ice-marginal lake Gornersee. The GPRI tracked the surface ice motion in line of sight over an area of ∼3 km2 down-glacier of Gornersee almost continuously during the drainage event. The displacement maps derived from the acquired interferograms capture the spatial distribution of the surface ice motion. Due to fast acquisition times of the microwave images, the GPRI was able to record sub-daily variations of the ice displacements, most likely caused by the impact of the Gornersee drainage on the ice motion of Gornergletscher. In situ point measurements of the ice displacement agree reasonably well with the results obtained by the GPRI and highlight the use of the GPRI for high-resolution measurements of glacier surface ice motion.
BibTeX:
@article{Riesen201153,
  author = {Riesen, P. and Strozzi, T. and Bauder, A. and Wiesmann, A. and Funk, M.},
  title = {Short-term surface ice motion variations measured with a ground-based portable real aperture radar Interferometer},
  journal = {Journal of Glaciology},
  year = {2011},
  volume = {57},
  number = {201},
  pages = {53-60},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958851547&doi=10.3189%2f002214311795306718&partnerID=40&md5=fba331e211206fb476eeb14e864963eb},
  doi = {10.3189/002214311795306718}
}
Santoro M, Beer C, Cartus O, Schmullius C, Shvidenko A, McCallum I, Wegmüller U and Wiesmann A (2011), "Retrieval of growing stock volume in boreal forest using hyper-temporal series of Envisat ASAR ScanSAR backscatter measurements", Remote Sensing of Environment. Vol. 115(2), pp. 490-507.
Abstract: Methods for the estimation of forest growing stock volume (GSV) are a major topic of investigation in the remote sensing community. The boreal zone contains almost 30% of global forest by area but measurements of forest resources are often outdated. Although past and current spaceborne synthetic aperture radar (SAR) backscatter data are not optimal for forest-related studies, a multi-temporal combination of individual GSV estimates can improve the retrieval as compared to the single-image case. This feature has been included in a novel GSV retrieval approach, hereafter referred to as the BIOMASAR algorithm. One innovative aspect of the algorithm is its independence from in situ measurements for model training. Model parameter estimates are obtained from central tendency statistics of the backscatter measurements for unvegetated and dense forest areas, which can be selected by means of a continuous tree canopy cover product, such as the MODIS Vegetation Continuous Fields product. In this paper, the performance of the algorithm has been evaluated using hyper-temporal series of C-band Envisat Advanced SAR (ASAR) images acquired in ScanSAR mode at 100m and 1km pixel size. To assess the robustness of the retrieval approach, study areas in Central Siberia (Russia), Sweden and Québec (Canada) have been considered. The algorithm validation activities demonstrated that the automatic approach implemented in the BIOMASAR algorithm performed similarly to traditional approaches based on in situ data. The retrieved GSV showed no saturation up to 300m3/ha, which represented almost the entire range of GSV at the study areas. The relative root mean square error (RMSE) was between 34.2% and 48.1% at 1km pixel size. Larger errors were obtained at 100m because of local errors in the reference datasets. Averaging GSV estimates over neighboring pixels improved the retrieval statistics substantially. For an aggregation factor of 10×10pixels, the relative RMSE was below 25%, regardless of the original resolution of the SAR data. 2010 Elsevier Inc.
BibTeX:
@article{Santoro2011490,
  author = {Santoro, M. and Beer, C. and Cartus, O. and Schmullius, C. and Shvidenko, A. and McCallum, I. and Wegmüller, U. and Wiesmann, A.},
  title = {Retrieval of growing stock volume in boreal forest using hyper-temporal series of Envisat ASAR ScanSAR backscatter measurements},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {2},
  pages = {490-507},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650875602&doi=10.1016%2fj.rse.2010.09.018&partnerID=40&md5=87625818a6dee66014cfd92a9fdd52d6},
  doi = {10.1016/j.rse.2010.09.018}
}
Schmitt M, Magnard C, Brehm T and Stilla U (2011), "Towards airborne single pass decimeter resolution SAR interferometry over urban areas", Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). Vol. 6952 LNCS, pp. 197-208.
Abstract: Airborne cross-track Synthetic Aperture Radar interferometers have the capability of deriving three-dimensional topographic information with just a single pass over the area of interest. In order to get a highly accurate height estimation, either a large interferometric baseline or a high radar frequency has to be used. The utilization of a millimeter wave SAR allows precise height estimation even for short baselines. Combined with a spatial resolution in the decimeter range, this enables the mapping of urban areas from airborne platforms. The side-looking SAR imaging geometry, however, leads to disturbing effects like layover and shadowing, which is even intensified by the shallow looking angle caused by the relatively low altitudes of airborne SAR systems. To solve this deficiency, enhanced InSAR processing strategies relying on multi-aspect and multi-baseline data, respectively, are shown to be necessary. 2011 Springer-Verlag.
BibTeX:
@article{Schmitt2011197,
  author = {Schmitt, M. and Magnard, C. and Brehm, T. and Stilla, U.},
  title = {Towards airborne single pass decimeter resolution SAR interferometry over urban areas},
  journal = {Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)},
  year = {2011},
  volume = {6952 LNCS},
  pages = {197-208},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80054014373&doi=10.1007%2f978-3-642-24393-6_17&partnerID=40&md5=35be4398f2c1af10c60f6378787decc7},
  doi = {10.1007/978-3-642-24393-6_17}
}
Schneebeli M and Matzler C (2011), "A radiative transfer model for an idealized and non-scattering atmosphere and its application for ground-based remote sensing", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 112(5), pp. 883-892.
Abstract: Inversion of tropospheric profiles from ground-based microwave measurements requires a simple and accurate model for calculating the brightness temperatures as received by the radiometer. In the first part, an analytic solution of the radiative transfer equation is derived for an exponentially decaying absorption coefficient and a linear temperature gradient. Based on the obtained analytic expressions, a discretized radiative transfer scheme is developed in the second part. The new scheme incorporates the generic behavior of the atmosphere with the effect that brightness temperatures can be modeled more accurately and with fewer grid points compared to commonly used radiative transfer schemes. The brightness temperature modeling accuracy was improved by a factor of six. The results suggest that the model could be employed for the retrieval of temperature and humidity profiles. 2010 Elsevier Ltd.
BibTeX:
@article{Schneebeli2011883,
  author = {Schneebeli, M. and Matzler, C.},
  title = {A radiative transfer model for an idealized and non-scattering atmosphere and its application for ground-based remote sensing},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2011},
  volume = {112},
  number = {5},
  pages = {883-892},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79451471808&doi=10.1016%2fj.jqsrt.2010.10.018&partnerID=40&md5=60d7b0a143f6713cb5a68977c29b86f9},
  doi = {10.1016/j.jqsrt.2010.10.018}
}
Schneebeli M and Matzler C (2011), "Spatiotemporal behavior of integrated water vapor", IEEE Geoscience and Remote Sensing Letters. Vol. 8(5), pp. 948-952.
Abstract: A time series of the hemispheric distribution of integrated water vapor (IWV) measured with the All-Sky Multi Wavelength Radiometer is analyzed by means of empirical orthogonal functions (EOFs). The data were acquired in February 2007 at the Zimmerwald Observatory in Switzerland. It is shown that the analysis of temporally demeaned time series yields information about passing fronts. With EOF analysis of the spatially demeaned time series, information about the spatial distribution of IWV is obtained. Our results also indicate that water vapor behaves like a conservative and passive tracer within the examined sampling volume and with the given temporal sampling resolution of 12 min. 2011 IEEE.
BibTeX:
@article{Schneebeli2011948,
  author = {Schneebeli, M. and Matzler, C.},
  title = {Spatiotemporal behavior of integrated water vapor},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  year = {2011},
  volume = {8},
  number = {5},
  pages = {948-952},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052341299&doi=10.1109%2fLGRS.2011.2144562&partnerID=40&md5=2d2f7ec46334ec761500285eccc1554c},
  doi = {10.1109/LGRS.2011.2144562}
}
Schneebeli M, Wolf S, Kunert N, Eugster W and Matzler C (2011), "Relating the X-band opacity of a tropical tree canopy to sapflow, rain interception and dew formation", Remote Sensing of Environment. Vol. 115(8), pp. 2116-2125.
Abstract: During summer and autumn 2007, a 11. GHz microwave radiometer was deployed in an experimental tree plantation in Sardinilla, Panama. The opacity of the tree canopy was derived from incoming brightness temperatures received on the ground. A collocated eddy-covariance flux tower measured water vapor fluxes and meteorological variables above the canopy. In addition, xylem sapflow of trees was measured within the flux tower footprint. We observed considerable diurnal differences between measured canopy opacities and modeled theoretical opacities that were closely linked to xylem sapflow. It is speculated that dielectric changes in the leaves induced by the sapflow are causing the observed diurnal changes. In addition, canopy intercepted rain and dew formation also modulated the diurnal opacity cycle. With an enhanced canopy opacity model accounting for water deposited on the leaves, we quantified the influence of canopy stored water (i.e. intercepted water and dew) on the opacity. A time series of dew formation and rain interception was directly monitored during a period of two weeks. We found that during light rainfall up to 60% of the rain amount is intercepted by the canopy whereas during periods of intense rainfall only 4% were intercepted. On average, 0.17. mm of dew was formed during the night. Dew evaporation contributed 5% to the total water vapor flux measured above the canopy. 2011 Elsevier Inc.
BibTeX:
@article{Schneebeli20112116,
  author = {Schneebeli, M. and Wolf, S. and Kunert, N. and Eugster, W. and Matzler, C.},
  title = {Relating the X-band opacity of a tropical tree canopy to sapflow, rain interception and dew formation},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {8},
  pages = {2116-2125},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957691036&doi=10.1016%2fj.rse.2011.04.016&partnerID=40&md5=bf7c405aab16f6de233cefaa22d16ce9},
  doi = {10.1016/j.rse.2011.04.016}
}
Stahli O, Matzler C, Murk A and Kampfer N (2011), "A surface-based imaging method for water vapor and liquid clouds using a scanning radiometer at 91 GHz", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(9), pp. 3273-3280.
Abstract: The Scanning Polarimetric Imaging RAdiometer a 91 GHz with an angular resolution of 0.5 circ was used to investigate the dynamics of the atmosphere. We introduced a new imaging method by continuously scanning the sky over a range of elevation angles in a fixed azimuth direction. The measurements were realized during three different situations: clear sky, sky with water clouds, and sky with cirrus clouds. In most situations, the scan direction was nearly parallel to the mean atmospheric flow. Particularly interesting structures were found in the images with water clouds. In contrast, cirrus clouds are highly transparent. Simulations of the applied imaging method helped to interpret the cloud images, particularly concerning the cloud movement. Characteristic shapes were identified as signatures of motions along the scan line, which were used to estimate the horizontal velocity of water clouds. It was also possible to estimate the integrated water vapor from the clear sky images. They allow a visualization of water vapor parcels. Some of these images contain similar signatures as the clouds, indicating advection of water vapor along the scan line. In the future, we plan to extend these measurements and to combine them with multifrequency observations. 2011 IEEE.
BibTeX:
@article{Stahli20113273,
  author = {Stahli, O. and Matzler, C. and Murk, A. and Kampfer, N.},
  title = {A surface-based imaging method for water vapor and liquid clouds using a scanning radiometer at 91 GHz},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {9},
  pages = {3273-3280},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052329808&doi=10.1109%2fTGRS.2011.2160269&partnerID=40&md5=cafae5e293c9de4ecfeb5a4707ea4a84},
  doi = {10.1109/TGRS.2011.2160269}
}
Strozzi T, Delaloye R, Poffet D, Hansmann J and Loew S (2011), "Surface subsidence and uplift above a headrace tunnel in metamorphic basement rocks of the Swiss Alps as detected by satellite SAR interferometry", Remote Sensing of Environment. Vol. 115(6), pp. 1353-1360.
Abstract: Surface subsidence associated with the construction of a headrace tunnel in the Swiss Alps at more than 2000 m above sea level (a.s.l.) has been detected at two locations with satellite differential Synthetic Aperture Radar (SAR) interferometry. At the first location, a subsidence trough of about 4 cm in the satellite line-of-sight direction following the headrace tunnel axes has been measured between August 1995 and August 1996. Similar values from SAR data of ascending and descending orbits indicate displacements in the vertical direction of the movement. In the second case, a symmetric cone of depression with a maximum displacement of about 4 cm between 1995 and 1997 has been observed above the tunnel. Differences in the results from satellite SAR data of ascending and descending orbits indicate that the direction of displacement in this second case was not entirely vertical. Large-scale consolidation associated with pore-pressure reduction in the rock mass arising from tunnel drainage at about 200-400 m depth beneath the topographical surface is believed to be the contributing mechanism (Zangerl et al., 2008a, 2008b). Evidence for this process is based on pore pressure recordings in nearby deep wells. In both areas, the subsidence was followed by a small uplift of about one centimeter between 1997 and 1999, after the tunnel was cased with permeable concrete segments. This partial recovery is also visible in pore pressure records and can be related to the elastic components of rock mass deformation. 2011 Elsevier Inc.
BibTeX:
@article{Strozzi20111353,
  author = {Strozzi, T. and Delaloye, R. and Poffet, D. and Hansmann, J. and Loew, S.},
  title = {Surface subsidence and uplift above a headrace tunnel in metamorphic basement rocks of the Swiss Alps as detected by satellite SAR interferometry},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {6},
  pages = {1353-1360},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79953166717&doi=10.1016%2fj.rse.2011.02.001&partnerID=40&md5=5a56c9e16b287e4237e0d65922455bbb},
  doi = {10.1016/j.rse.2011.02.001}
}
Tanase M, de la Riva J, Santoro M, Pérez-Cabello F and Kasischke E (2011), "Sensitivity of SAR data to post-fire forest regrowth in Mediterranean and boreal forests", Remote Sensing of Environment. Vol. 115(8), pp. 2075-2085.
Abstract: Disturbed forests may need decades to reach a mature stage and optically-based vegetation indices are usually poorly suited for monitoring purposes due to the rapid saturation of the signal with increasing canopy cover. Spaceborne synthetic aperture radar (SAR) data provide an alternate monitoring approach since the backscattered microwave energy is sensitive to the vegetation structure. Images from two regions in Spain and Alaska were used to analyze SAR metrics (cross-polarized backscatter and co-polarized interferometric coherence) from regrowing forests previously affected by fire. TerraSAR-X X-band backscatter showed the lowest sensitivity to forest regrowth, with the average backscatter increasing by 1-2. dB between the most recent fire scar and the unburned forest. Increased sensitivity (around 3-4. dB) was observed for C-band Envisat Advanced Synthetic Aperture (ASAR) backscatter. The Advanced Land Observing Satellite (ALOS) Phased Array-type L-band Synthetic Aperture Radar (PALSAR) L-band backscatter presented the highest dynamic range from unburned to recently burned forests (approximately 8. dB). The interferometric coherence showed low sensitivity to forest regrowth at all SAR frequencies. For Mediterranean forests, five phases of forest regrowth were discerned whereas for boreal forest, up to four different regrowth phases could be discerned with L-band SAR data. In comparison, the Normalized Difference Vegetation Index (NDVI) provided reliable differentiation only for the most recent development stages. The results obtained were consistent in both environments. 2011 Elsevier Inc.
BibTeX:
@article{Tanase20112075,
  author = {Tanase, M. and de la Riva, J. and Santoro, M. and Pérez-Cabello, F. and Kasischke, E.},
  title = {Sensitivity of SAR data to post-fire forest regrowth in Mediterranean and boreal forests},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {8},
  pages = {2075-2085},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957624015&doi=10.1016%2fj.rse.2011.04.009&partnerID=40&md5=e9744288c78f2275834aba9d2022a5ba},
  doi = {10.1016/j.rse.2011.04.009}
}
Teatini P, Tosi L and Strozzi T (2011), "Quantitative evidence that compaction of Holocene sediments drives the present land subsidence of the Po Delta, Italy", Journal of Geophysical Research: Solid Earth. Vol. 116(8) Blackwell Publishing Ltd.
Abstract: Deltas are highly dynamic coastal systems that over the last few decades have generally experienced a substantial area loss caused by trapping of river sediments in upland drainage basins as well as land subsidence due to natural and anthropogenic causes. A major example is the Po Delta in the Mediterranean in northeastern Italy. This area has experienced as much as 3 m of land subsidence from the 1930s to the 1970s primarily because of the extraction of gas-bearing waters. However, present subsidence rates are largely unknown and the ground settlement is supposedly controlled by natural long-term deep processes. We have combined radar Interferometric Point Target Analysis (IPTA) with previous geomorphological investigations on aerial/satellite images and seismic surveys, and geochronological data from core samples and geomechanical in situ tests, to assess the current sinking of the delta and to understand the processes controlling the vertical movement. The high density of the measurable point targets (more than 15,000) allows characterization of the spatial variation in the vertical land motions (VLM), ranging from -1 to -15 mm/yr. We find that subsidence rates are significantly correlated with the age of highly compressible Holocene deposits that compose the shallowest 30-40 m of the sedimentary sequence. A typical log-type consolidation equation applicable at the scale of the entire delta has been obtained. We conclude that the consolidation of late Holocene sediments is the major cause of the present land subsidence in the Po River delta. This finding has significant impact on the understanding of many other modern deltas that were formed in the lower Holocene epoch. Copyright 2011 by the American Geophysical Union.
BibTeX:
@article{Teatini2011,
  author = {Teatini, P. and Tosi, L. and Strozzi, T.},
  title = {Quantitative evidence that compaction of Holocene sediments drives the present land subsidence of the Po Delta, Italy},
  journal = {Journal of Geophysical Research: Solid Earth},
  publisher = {Blackwell Publishing Ltd},
  year = {2011},
  volume = {116},
  number = {8},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052309695&doi=10.1029%2f2010JB008122&partnerID=40&md5=9c747f5089914a39703454d212c92842},
  doi = {10.1029/2010JB008122}
}
Triebnig G, Diamandi A, Hall R, Malnes E, Marklund L, Metsamaki S, Nagler T, Pulliainen J, Rott H, Schiller C, Solberg R and Wiesmann A (2011), "CryoLand - GMES service snow and land ice - Interoperability, service integration and user access", IFIP Advances in Information and Communication Technology. Vol. 359 AICT, pp. 341-348. Springer New York LLC.
Abstract: The CryoLand project implements and validates a standardized and sustainable service on snow and land ice monitoring as a Downstream Service of GMES. It will provide geospatial product coverages of seasonal snow (snow extent, snow mass, melt state), glaciers (area, snow / ice extent, ice velocities, glacier dammed lakes), and lake / river ice (extent, temporal variations, snow burden) derived from Earth observation (EO) satellite data. Processing lines and a service infrastructure will be developed on top of existing Web service environments supporting the publication, provision and chaining of involved geospatial data services. The CryoLand service architecture commits INSPIRE, OGC, and OASIS standards specifically respecting HMA and GENESIS frameworks. User information services offering discovery, view and download functions will be provided. 2011 IFIP International Federation for Information Processing.
BibTeX:
@article{Triebnig2011341,
  author = {Triebnig, G. and Diamandi, A. and Hall, R. and Malnes, E. and Marklund, L. and Metsamaki, S. and Nagler, T. and Pulliainen, J. and Rott, H. and Schiller, C. and Solberg, R. and Wiesmann, A.},
  title = {CryoLand - GMES service snow and land ice - Interoperability, service integration and user access},
  journal = {IFIP Advances in Information and Communication Technology},
  publisher = {Springer New York LLC},
  year = {2011},
  volume = {359 AICT},
  pages = {341-348},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960797950&doi=10.1007%2f978-3-642-22285-6_37&partnerID=40&md5=0a808261d251dd743ffff49a1c4e313b},
  doi = {10.1007/978-3-642-22285-6_37}
}
Volksch I, Schwank M and Matzler C (2011), "L-band reflectivity of a furrowed soil surface", IEEE Transactions on Geoscience and Remote Sensing. Vol. 49(6 PART 1), pp. 1957-1966.
Abstract: In a combined experimental and model study, we investigated the thermal L-band signatures of a sandy soil with periodic topography (furrows) with dimensions close to the observation wavelength of 21 cm. Measurements were carried out with a radiometer mounted on a tower and aimed at a soil box with an artificially prepared furrowed soil surface. Corresponding reflectivities were derived from brightness temperature measurements performed under dry and moist conditions, with the furrow direction either along or perpendicular to the plane of incidence. Results showed that the furrows had a pronounced effect on the reflectivity, depending on the polarization of the observed radiance, the direction of the furrows, and the soil moisture. A physical reflectivity model for dielectric periodic surfaces was used to explain the soil reflectivities measured for the different furrow directions and soil-water contents. Using this model improved the agreement between the measured and modeled reflectivities considerably compared to the Fresnel reflectivities. The observed dependence of soil reflectivity on furrow orientation and soil moisture could be reproduced by the reflectivity model. The quantitative agreement with the observed reflectivities was further improved by using a simple empirical approach to consider the small-scale heterogeneity of the top soil layer. 2011 IEEE.
BibTeX:
@article{Volksch20111957,
  author = {Volksch, I. and Schwank, M. and Matzler, C.},
  title = {L-band reflectivity of a furrowed soil surface},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2011},
  volume = {49},
  number = {6 PART 1},
  pages = {1957-1966},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957650214&doi=10.1109%2fTGRS.2010.2091720&partnerID=40&md5=f5ef0229775a846e056531d6f6b0691b},
  doi = {10.1109/TGRS.2010.2091720}
}
Wegmüller U, Santoro M, Mattia F, Balenzano A, Satalino G, Marzahn P, Fischer G, Ludwig R and Floury N (2011), "Progress in the understanding of narrow directional microwave scattering of agricultural fields", Remote Sensing of Environment. Vol. 115(10), pp. 2423-2433.
Abstract: Directional microwave scattering, as investigated in this study, is characterized by a strong and narrow scattering pattern that varies strongly for only minor aspect angle changes. As was noted already in the past directional scattering is relevant for applications and cannot just be ignored. The overall objective of our work was to better understand directional scattering. Suited space- and airborne SAR data over several agricultural sites together with related in-situ information were collected for this purpose. Directional scattering was identified by comparison of backscattering acquired with only slightly different aspect angles as available from ERS-ENVISAT pairs with significantly different Doppler Centroids or by comparing azimuth spectrum sub-bands with slightly different Doppler Centroid. Major progress achieved in this work includes the much improved experimental evidence available and significant improvements in the understanding of the scatter phenomenon through the developed scatter model. Good progress was also made in the detection of directional scattering. 2011 Elsevier Inc.
BibTeX:
@article{Wegmuller20112423,
  author = {Wegmüller, U. and Santoro, M. and Mattia, F. and Balenzano, A. and Satalino, G. and Marzahn, P. and Fischer, G. and Ludwig, R. and Floury, N.},
  title = {Progress in the understanding of narrow directional microwave scattering of agricultural fields},
  journal = {Remote Sensing of Environment},
  year = {2011},
  volume = {115},
  number = {10},
  pages = {2423-2433},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960741618&doi=10.1016%2fj.rse.2011.04.026&partnerID=40&md5=ed0c4e32b3965e14692c2421dc777c66},
  doi = {10.1016/j.rse.2011.04.026}
}
Wegmüller U, Werner CL, Frey O, Strozzi T and Santoro M (2011), "Multi-pass ERS-ENVISAT cross-interferometry methods and results", In Proc. FRINGE 2011. Frascati, Italy, September, 2011.
Abstract: ERS-ENVISAT Tandem (EET) cross-interferometry (CInSAR) pairs are characterized by long 2km baselines and short 28 minute time intervals. Over some sites multiple pairs are available. In our work we discuss multi-pass interferometric techniques and investigate for several applications, including DEM generation, mapping of fast motions and grounding line mapping for Antarctic ice sheets, the use of multiple EET pairs.
BibTeX:
@inproceedings{wegmullerWernerFreyStrozziSantoro2011,
  author = {Urs Wegmüller and Charles L. Werner and Othmar Frey and Tazio Strozzi and Maurizio Santoro},
  title = {Multi-pass ERS-ENVISAT cross-interferometry methods and results},
  booktitle = {Proc. FRINGE 2011},
  year = {2011}
}
Werner CL, Wegmüller U, Frey O and Santoro M (2011), "Interferometric processing of PALSAR Wide-Beam SCANSAR Data", In Proc. FRINGE 2011. Frascati, Italy, September, 2011.
Abstract: Processing of ScanSAR data for interferometric applications requires careful attention to the phase and position accuracy to obtain interferometric products with high correlation and continuous phase across the bursts. We describe an interferometric processing system developed for ScanSAR data acquired by the ALOS PALSAR instrument able to produce differential interferometric products with 350 km swath width that are without visible phase discontinuities between ScanSAR beams.
BibTeX:
@inproceedings{wernerWegmullerFreySantoro2011,
  author = {Charles L. Werner and Urs Wegmüller and Othmar Frey and Maurizio Santoro},
  title = {Interferometric processing of PALSAR Wide-Beam SCANSAR Data},
  booktitle = {Proc. FRINGE 2011},
  year = {2011}
}
Wiesmann A and Gruner U (2011), "Radar interferometry in use for monitoring the stability of extensive cliffs [Radar-lnterferometrie im Einsatz fuer die Stabilitaetsueberwachung von grossflaechigen Felswaenden]", Bulletin fuer Angewandte Geologie. Vol. 16(1), pp. 51-55. Ver. Schweizerischer Petroleum Geol. und Ing..
Abstract: Radar interferometry is widely used for monitoring terrain movement from space. With the availability of portable terrestrial radar interferometers this technique is now also applied locally. The terrestrial radar interferometry allows to image the movement along the line of sight of large rockwatls with-in mm accuracy. This new technique is currently used at several locations in Switzerland as an early warning system to detect rock movements along important traffic lines.
BibTeX:
@article{Wiesmann201151,
  author = {Wiesmann, A. and Gruner, U.},
  title = {Radar interferometry in use for monitoring the stability of extensive cliffs [Radar-lnterferometrie im Einsatz fuer die Stabilitaetsueberwachung von grossflaechigen Felswaenden]},
  journal = {Bulletin fuer Angewandte Geologie},
  publisher = {Ver. Schweizerischer Petroleum Geol. und Ing.},
  year = {2011},
  volume = {16},
  number = {1},
  pages = {51-55},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85016254716&doi=10.5169%2fseals-327741&partnerID=40&md5=3b5bce8d9207448bf4a41800008b896f},
  doi = {10.5169/seals-327741}
}
Zacharias S, Bogena H, Samaniego L, Mauder M, Fuß R, Putz T, Frenzel M, Schwank M, Baessler C, Butterbach-Bahl K, Bens O, Borg E, Brauer A, Dietrich P, Hajnsek I, Helle G, Kiese R, Kunstmann H, Klotz S, Munch J, Papen H, Priesack E, Schmid H, Steinbrecher R, Rosenbaum U, Teutsch G and Vereecken H (2011), "A network of terrestrial environmental observatories in Germany", Vadose Zone Journal. Vol. 10(3), pp. 955-973.
Abstract: Multi compartment and multiscale long-term observation and research are important prerequisites to tackling the scientific challenges resulting from climate and global change. Long-term monitoring programs are cost intensive and require high analytical standards, however, and the gain of knowledge often requires longer observation times. Nevertheless, several environmental research networks have been established in recent years, focusing on the impact of climate and land use change on terrestrial ecosystems. From 2008 onward, a network of Terrestrial Environmental Observatories (TERENO) has been established in Germany as an interdisciplinary research program that aims to observe and explore the long-term ecological, social, and economic impacts of global change at the regional level. State-of-the-art methods from the field of environmental monitoring, geophysics, and remote sensing will be used to record and analyze states and fluxes for different environmental compartments from groundwater through the vadose zone, surface water, and biosphere, up to the lower atmosphere. Soil Science Society of America.
BibTeX:
@article{Zacharias2011955,
  author = {Zacharias, S. and Bogena, H. and Samaniego, L. and Mauder, M. and Fuß, R. and Putz, T. and Frenzel, M. and Schwank, M. and Baessler, C. and Butterbach-Bahl, K. and Bens, O. and Borg, E. and Brauer, A. and Dietrich, P. and Hajnsek, I. and Helle, G. and Kiese, R. and Kunstmann, H. and Klotz, S. and Munch, J.C. and Papen, H. and Priesack, E. and Schmid, H.P. and Steinbrecher, R. and Rosenbaum, U. and Teutsch, G. and Vereecken, H.},
  title = {A network of terrestrial environmental observatories in Germany},
  journal = {Vadose Zone Journal},
  year = {2011},
  volume = {10},
  number = {3},
  pages = {955-973},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860394701&doi=10.2136%2fvzj2010.0139&partnerID=40&md5=e66c6b14c4135d41b997b02d62d80fde},
  doi = {10.2136/vzj2010.0139}
}
Bitelli G, Bonsignore F, Carbognin L, Ferretti A, Strozzi T, Teatini P, Tosi L and Vittuari L (2010), "Radar interferometry-based mapping of the present land subsidence along the low-lying northern Adriatic coast of Italy", In IAHS-AISH Publication. Vol. 339, pp. 279-286.
Abstract: The northern Adriatic coastal area, Italy (from the Veneto region northward, and to the Romagna region to the south), is characterized by low-lying environments such as lagoons, e.g. those of Venice and of the Valli di Comacchio, wetlands and deltas, such as that of the Po River delta, and reclaimed farmland and beaches subjected to marked anthropogenic pressure. The coastal area is characterized by an elevation generally well below the mean sea level (down to -4 m m.s.l.) and never exceeds 2 m above m.s.l. Man-induced land subsidence has greatly affected the whole coastal area over the 20th century, and especially from the 1950s and the 1970s, when over-exploitation of subsurface fluids was responsible for the occurrence of general lowering. Although the sinking rates have significantly decreased over the last decades, land subsidence is still a process threatening the entire coastal environment. In this study we report a recent investigation aimed at mapping the vertical displacements recorded in the period 1992-2000 on the 20-30 km wide and 250-km long coastal area from the Tagliamento River to the north, to the town of Rimini to the south. Measurements have been carried out by Persistent Scatterer Interferometry (PSI) using levelling and GPS records to reference the interferometric solution. The results identify the variability of the ground movements that are presently occurring along the northern Adriatic coastline. Substantially stable areas, the most important of which are the cities of Venice and Ravenna and their surroundings, contrast with subsidence rates of more than 10 mm/year recorded in some parts of the Po River delta and to the south. The observed land displacements have been associated with the geological features of the study region, i.e. tectonics and differential consolidation of the Middle-Upper Pleistocene and Holocene deposits, and to anthropogenic activities, mainly groundwater withdrawal from the Upper Pleistocene-Holocene alluvial deposits and more locally peatland oxidation in reclaimed areas and gas exploitation from Plio-Pleistocene reservoirs. Copyright 2010 IAHS Press.
BibTeX:
@conference{Bitelli2010279,
  author = {Bitelli, G. and Bonsignore, F. and Carbognin, L. and Ferretti, A. and Strozzi, T. and Teatini, P. and Tosi, L. and Vittuari, L.},
  title = {Radar interferometry-based mapping of the present land subsidence along the low-lying northern Adriatic coast of Italy},
  booktitle = {IAHS-AISH Publication},
  year = {2010},
  volume = {339},
  pages = {279-286},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79952634892&partnerID=40&md5=cda540d47c48ba65ecc2ed9a1f083338}
}
Casu F, Manconi A, Pepe A, Manzo M and Lanari R (2010), "Advances in the generation of deformation time series from SAR data sequences in areas affected by large dynamics", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 2618-2621.
Abstract: We propose advances on the generation of deformation time series in areas affected by large deformation dynamics, where the exploitation of the differential SAR phase can be strongly limited by severe misregistration errors or by very high fringe rates. First, to overcome the former issue, we present an extension of the amplitude-based Pixel-Offset (PO) analyses by applying the Small BAseline Subset (SBAS) strategy, in order to move from the investigation of single (large) deformation events to that of dynamic phenomena. Secondly, to handle the high fringe rate interferograms, we subtract from them properly generated synthetic deformation models allowing us to reduce the fringe rate, thus helping the phase unwrapping step. The proposed approaches have been tested on ASAR-ENVISAT data acquired on Galápagos Islands and validated via continuous GPS measurements. 2010 IEEE.
BibTeX:
@conference{Casu20102618,
  author = {Casu, F. and Manconi, A. and Pepe, A. and Manzo, M. and Lanari, R.},
  title = {Advances in the generation of deformation time series from SAR data sequences in areas affected by large dynamics},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2010},
  pages = {2618-2621},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650908640&doi=10.1109%2fIGARSS.2010.5651926&partnerID=40&md5=35cc5413748c3ca755c4314073db1e3c},
  doi = {10.1109/IGARSS.2010.5651926}
}
Eriksson L, Borenas K, Dierking W, Berg A, Santoro M, Pemberton P, Lindh H and Karlson B (2010), "Evaluation of new spaceborne SAR sensors for sea-ice monitoring in the Baltic Sea", Canadian Journal of Remote Sensing. Vol. 36, pp. S56-S73.
Abstract: In this study, synthetic aperture radar (SAR) data from the Advanced Land Observing Satellite (ALOS) and the Envisat, RADARSAT-2, and TerraSAR-X satellites were compared to evaluate their usefulness for sea-ice monitoring in the Baltic Sea. Radar signature characteristics at different frequencies, polarizations, and spatial resolutions are presented for three examples from 2009. C-band like-polarization data, which have been used for operational sea-ice mapping since the early 1990s, serve as a reference. Advantages and disadvantages were identified for the different SAR systems and imaging modes. One conclusion is that cross-polarized data improve the discrimination between sea ice and open water. Another observation is that it is easier to identify ice ridges in L-band data than in images from shorter wavelengths. The information content of X- and C-band images is largely equivalent, whereas L-band data provide complementary information. L-band SAR also seems to be less sensitive to wet snow cover on the ice. 2010, Taylor & Francis Group, LLC. All rights reserved.
BibTeX:
@article{Eriksson2010S56,
  author = {Eriksson, L.E.B. and Borenas, K. and Dierking, W. and Berg, A. and Santoro, M. and Pemberton, P. and Lindh, H. and Karlson, B.},
  title = {Evaluation of new spaceborne SAR sensors for sea-ice monitoring in the Baltic Sea},
  journal = {Canadian Journal of Remote Sensing},
  year = {2010},
  volume = {36},
  pages = {S56-S73},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77956154903&doi=10.5589%2fm10-020&partnerID=40&md5=995d135b5b3a54e25679ec13b5cc6d34},
  doi = {10.5589/m10-020}
}
Fransson J, Pantze A, Eriksson L, Soja M and Santoro M (2010), "Mapping of wind-thrown forests using satellite SAR images", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 1242-1245.
Abstract: The study focuses on investigation and evaluation of wind-thrown forest mapping using satellite remotely sensed data from three synthetic aperture radar (SAR) sensors. The study is carried out at Remningstorp, a test site in the south of Sweden dominated by coniferous forest, where trees were manual felled to simulate wind-thrown forest. The satellite data consisted of time series of HH polarized SAR images acquired by the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR), Radarsat-2 (C-band) and TerraSAR-X (X-band). The results from visual interpretation of SAR images acquired before and after the simulated wind-throw together with corresponding ratio images show that ALOS PALSAR HH polarized intensity images are not able to detect wind-thrown forest, probably due to too coarse spatial resolution. In contrast, the wind-thrown forest is clearly visible in the Radarsat-2 and TerraSAR-X HH polarized images, implying that it may be possible to develop a new application using these SAR data for mapping of wind-thrown forests. 2010 IEEE.
BibTeX:
@conference{Fransson20101242,
  author = {Fransson, J.E.S. and Pantze, A. and Eriksson, L.E.B. and Soja, M.J. and Santoro, M.},
  title = {Mapping of wind-thrown forests using satellite SAR images},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2010},
  pages = {1242-1245},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650860742&doi=10.1109%2fIGARSS.2010.5654183&partnerID=40&md5=43bd5a67d70c1f8ec716a56f66dcfc06},
  doi = {10.1109/IGARSS.2010.5654183}
}
Frey O and Meier E (2010), "3D SAR imaging of a forest using airborne MB-SAR data at L- and P-band: Data processing and analysis", In Proc. European Conf. Synthetic Aperture Radar. , pp. 166-169. Institute of Electrical and Electronics Engineers Inc..
Abstract: Using a time-domain back-projection based focusing algorithm in combination with three tomographic focusing techniques (multilook standard beamforming, robust Capon beamforming, and MUSIC) a 3D volume containing a forested area has been tomographically imaged at L- and P-band. In this paper, we present further results and insights obtained by processing and analyzing these data sets with respect to the localization of the scattering sources using the three different focusing techniques, as well as for both, the two frequency bands and the different polarimetric channels. VDE VERLAG GMBH · Berlin · Offenbach.
BibTeX:
@conference{Frey2010166,
  author = {Frey, O. and Meier, E.},
  title = {3D SAR imaging of a forest using airborne MB-SAR data at L- and P-band: Data processing and analysis},
  booktitle = {Proc. European Conf. Synthetic Aperture Radar},
  publisher = {Institute of Electrical and Electronics Engineers Inc.},
  year = {2010},
  pages = {166-169},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84985863702&partnerID=40&md5=5777ed82ebfcd1c421bce22a41b9f00b}
}
Frey O and Meier E (2010), "Analyzing tomographic SAR data of a forest with respect to frequency, polarization, and focusing technique", In Proc. IEEE Int. Geosci. Remote Sens. Symp.. , pp. 150-153.
Abstract: In this paper, two fully-polarimetric tomographic SAR data sets of a forested area, at L-band and P-band, are analyzed with respect to the localization of scattering sources and scattering mechanisms. In particular, the 3D SAR data is examined regarding the performance of three different tomographic focusing techniques multilook standard beamforming, robust Capon beamforming, and MUSIC, as well as for both, the two frequency bands and the different polarimetric channels. 2010 IEEE.
BibTeX:
@conference{Frey2010150,
  author = {Frey, O. and Meier, E.},
  title = {Analyzing tomographic SAR data of a forest with respect to frequency, polarization, and focusing technique},
  booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
  year = {2010},
  pages = {150-153},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650861110&doi=10.1109%2fIGARSS.2010.5654438&partnerID=40&md5=d8849c800d27702cec9cdd9838503b32},
  doi = {10.1109/IGARSS.2010.5654438}
}
Jehle M, Frey O, Small D and Meier E (2010), "Measurement of ionospheric tec in spaceborne sar data", IEEE Transactions on Geoscience and Remote Sensing. Vol. 48(6), pp. 2460-2468.
Abstract: The propagation of spaceborne radar signals operating at L-band frequency or below can be seriously affected by the ionosphere. At high states of solar activity, Faraday rotation (FR) and signal path delays disturb radar polarimetry and reduce resolution in range and azimuth. While these effects are negligible at X-band, FR and the frequency-dependent path delays can become seriously problematic starting at L-band. For quality assurance and calibration purposes, existing L-band or potential spaceborne P-band missions require the estimation of the ionospheric state before or during the data take. This paper introduces two approaches for measuring the ionospheric total electron content (TEC) from single-polarized spaceborne SAR data. The two methods are demonstrated using simulations. Both methods leverage knowledge of the frequency-dependent path delay through the ionosphere: The first estimates TEC from the phase error of the filter mismatch, while the second gauges path-delay differences between up and down chirps. FR, mean (direct current) offsets, and noise contributions are also considered in the simulations. Finally, possibilities for further methodological improvements are discussed. 2006 IEEE.
BibTeX:
@article{Jehle20102460,
  author = {Jehle, M. and Frey, O. and Small, D. and Meier, E.},
  title = {Measurement of ionospheric tec in spaceborne sar data},
  journal = {IEEE Transactions on Geoscience and Remote Sensing},
  year = {2010},
  volume = {48},
  number = {6},
  pages = {2460-2468},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77952586225&doi=10.1109%2fTGRS.2010.2040621&partnerID=40&md5=d79bc651dbc78a466d1d8ba5c74c5d21},
  doi = {10.1109/TGRS.2010.2040621}
}
Lanari R, Berardino P, Bonano M, Casu F, Manconi A, Manunta M, Manzo M, Pepe A, Pepe S, Sansosti E, Solaro G, Tizzani P and Zeni G (2010), "Surface displacements associated with the L'Aquila 2009 Mw 6.3 earthquake (central Italy): New evidence from SBAS-DInSAR time series analysis", Geophysical Research Letters. Vol. 37(20) Blackwell Publishing Ltd.
Abstract: We investigate the surface displacements in the area affected by the April 2009 L'Aquila earthquake (Central Italy) through an advanced DInSAR analysis. In particular, we apply the SBAS approach to retrieve deformation maps and displacement time series from ENVISAT data acquired between February 2003 and October 2009 and from COSMO-SkyMed data relevant to the six-month interval following the earthquake. Our analysis shows no evidence of pre-seismic surface deformation at the 35-day temporal sampling of the ENVISAT sensor. On the other hand, by benefiting of the high spatial resolution and temporal sampling of the COSMO-SkyMed satellites, we measure post-seismic displacements at an unprecedented level of detail for a DInSAR analysis. This allows us to identify three main areas continuing to deform after the earthquake. In addition, our modeling shows that post-seismic displacements are very likely related to the fault afterslip, since their decay times are on the order of 10 1-102 days. 2010 by the American Geophysical Union.
BibTeX:
@article{Lanari2010,
  author = {Lanari, R. and Berardino, P. and Bonano, M. and Casu, F. and Manconi, A. and Manunta, M. and Manzo, M. and Pepe, A. and Pepe, S. and Sansosti, E. and Solaro, G. and Tizzani, P. and Zeni, G.},
  title = {Surface displacements associated with the L'Aquila 2009 Mw 6.3 earthquake (central Italy): New evidence from SBAS-DInSAR time series analysis},
  journal = {Geophysical Research Letters},
  publisher = {Blackwell Publishing Ltd},
  year = {2010},
  volume = {37},
  number = {20},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78049326388&doi=10.1029%2f2010GL04