A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska
Landslides can have complex, spatially strongly inhomogeneous surface displacement fields with discontinuities from multiple active lobes that are deforming while failing on nested slip surfaces at different depths. For synthetic aperture radar interferometry (InSAR), particularly at lower resolutio...
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ftdoajarticles:oai:doaj.org/article:5fa234827a87402faf8d100df3d47a11 2023-05-15T16:20:45+02:00 A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska Bernhard Rabus Manuele Pichierri 2018-06-01T00:00:00Z https://doi.org/10.3390/rs10070995 https://doaj.org/article/5fa234827a87402faf8d100df3d47a11 EN eng MDPI AG http://www.mdpi.com/2072-4292/10/7/995 https://doaj.org/toc/2072-4292 2072-4292 doi:10.3390/rs10070995 https://doaj.org/article/5fa234827a87402faf8d100df3d47a11 Remote Sensing, Vol 10, Iss 7, p 995 (2018) InSAR landslide phase unwrapping phase demodulation TerraSAR-X RADARSAT-2 ALOS-1 ERS Science Q article 2018 ftdoajarticles https://doi.org/10.3390/rs10070995 2022-12-31T11:05:53Z Landslides can have complex, spatially strongly inhomogeneous surface displacement fields with discontinuities from multiple active lobes that are deforming while failing on nested slip surfaces at different depths. For synthetic aperture radar interferometry (InSAR), particularly at lower resolutions, these characteristics can cause significant aliasing of the wrapped phase. In combination with steep terrain and seasonal snow cover, causing layover and temporal decorrelation, respectively, traditional phase unwrapping can become unfeasible, even after topographic phase contributions have been removed with an external high-resolution digital surface model (DSM). We present a novel method: warp demodulation that reduces the complexity of the phase unwrapping problem for noisy and/or aliased, low-resolution interferograms of discontinuous landslide displacement. The key input to our warp demodulation method is a single (or several) reference interferogram(s) from a high-resolution sensor mode such as TerraSAR-X Staring Spotlight with short temporal baseline and good coherence to allow localization of phase discontinuities and accurate unwrapping. The task of constructing suitable phase surfaces to approximate individual to-be-demodulated interferograms from the reference interferogram is made difficult by strong and spatially inhomogeneous temporal, seasonal, and interannual variations of the landslide with individual lobes accelerating or decelerating at different rates. This prevents using simple global scaling of the reference. Instead, our method uses an irregular grid of small patches straddling strong spatial gradients and phase discontinuities in the reference to find optimum local scaling factors that minimize the residual phase gradients across the discontinuities after demodulation. Next, for each to-be-demodulated interferogram, from these measurements we interpolate a spatially smooth global scaling function, which is then used to scale the (discontinuous) reference. Demodulation with the scaled ... Article in Journal/Newspaper glacier Alaska Directory of Open Access Journals: DOAJ Articles Remote Sensing 10 7 995 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
InSAR landslide phase unwrapping phase demodulation TerraSAR-X RADARSAT-2 ALOS-1 ERS Science Q |
spellingShingle |
InSAR landslide phase unwrapping phase demodulation TerraSAR-X RADARSAT-2 ALOS-1 ERS Science Q Bernhard Rabus Manuele Pichierri A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
topic_facet |
InSAR landslide phase unwrapping phase demodulation TerraSAR-X RADARSAT-2 ALOS-1 ERS Science Q |
description |
Landslides can have complex, spatially strongly inhomogeneous surface displacement fields with discontinuities from multiple active lobes that are deforming while failing on nested slip surfaces at different depths. For synthetic aperture radar interferometry (InSAR), particularly at lower resolutions, these characteristics can cause significant aliasing of the wrapped phase. In combination with steep terrain and seasonal snow cover, causing layover and temporal decorrelation, respectively, traditional phase unwrapping can become unfeasible, even after topographic phase contributions have been removed with an external high-resolution digital surface model (DSM). We present a novel method: warp demodulation that reduces the complexity of the phase unwrapping problem for noisy and/or aliased, low-resolution interferograms of discontinuous landslide displacement. The key input to our warp demodulation method is a single (or several) reference interferogram(s) from a high-resolution sensor mode such as TerraSAR-X Staring Spotlight with short temporal baseline and good coherence to allow localization of phase discontinuities and accurate unwrapping. The task of constructing suitable phase surfaces to approximate individual to-be-demodulated interferograms from the reference interferogram is made difficult by strong and spatially inhomogeneous temporal, seasonal, and interannual variations of the landslide with individual lobes accelerating or decelerating at different rates. This prevents using simple global scaling of the reference. Instead, our method uses an irregular grid of small patches straddling strong spatial gradients and phase discontinuities in the reference to find optimum local scaling factors that minimize the residual phase gradients across the discontinuities after demodulation. Next, for each to-be-demodulated interferogram, from these measurements we interpolate a spatially smooth global scaling function, which is then used to scale the (discontinuous) reference. Demodulation with the scaled ... |
format |
Article in Journal/Newspaper |
author |
Bernhard Rabus Manuele Pichierri |
author_facet |
Bernhard Rabus Manuele Pichierri |
author_sort |
Bernhard Rabus |
title |
A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
title_short |
A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
title_full |
A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
title_fullStr |
A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
title_full_unstemmed |
A New InSAR Phase Demodulation Technique Developed for a Typical Example of a Complex, Multi-Lobed Landslide Displacement Field, Fels Glacier Slide, Alaska |
title_sort |
new insar phase demodulation technique developed for a typical example of a complex, multi-lobed landslide displacement field, fels glacier slide, alaska |
publisher |
MDPI AG |
publishDate |
2018 |
url |
https://doi.org/10.3390/rs10070995 https://doaj.org/article/5fa234827a87402faf8d100df3d47a11 |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
Remote Sensing, Vol 10, Iss 7, p 995 (2018) |
op_relation |
http://www.mdpi.com/2072-4292/10/7/995 https://doaj.org/toc/2072-4292 2072-4292 doi:10.3390/rs10070995 https://doaj.org/article/5fa234827a87402faf8d100df3d47a11 |
op_doi |
https://doi.org/10.3390/rs10070995 |
container_title |
Remote Sensing |
container_volume |
10 |
container_issue |
7 |
container_start_page |
995 |
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1766008734650204160 |