Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations
Area-based measurements of snow water equivalent (SWE) are important for understanding earth system processes such as glacier mass balance, winter hydrological storage in drainage basins, and ground thermal regimes. Remote sensing techniques are ideally suited for wide-scale area-based mapping with...
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2022
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00060775 2023-05-15T16:22:30+02:00 Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations Eppler, Jayson Rabus, Bernhard Morse, Peter 2022-04 electronic https://doi.org/10.5194/tc-16-1497-2022 https://noa.gwlb.de/receive/cop_mods_00060775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00060351/tc-16-1497-2022.pdf https://tc.copernicus.org/articles/16/1497/2022/tc-16-1497-2022.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-16-1497-2022 https://noa.gwlb.de/receive/cop_mods_00060775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00060351/tc-16-1497-2022.pdf https://tc.copernicus.org/articles/16/1497/2022/tc-16-1497-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/tc-16-1497-2022 2022-05-01T23:09:44Z Area-based measurements of snow water equivalent (SWE) are important for understanding earth system processes such as glacier mass balance, winter hydrological storage in drainage basins, and ground thermal regimes. Remote sensing techniques are ideally suited for wide-scale area-based mapping with the most commonly used technique to measure SWE being passive microwave, which is limited to coarse spatial resolutions of 25 km or greater and to areas without significant topographic variation. Passive microwave also has a negative bias for large SWE. Another method is repeat-pass synthetic aperture radar interferometry (InSAR) that allows measurement of SWE change at much higher spatial resolution. However, it has not been widely adopted because (1) the phase unwrapping problem has not been robustly addressed, especially for interferograms with poor coherence, and (2) SWE change maps scaled directly from repeat-pass interferograms are not an absolute measurement but contain unknown offsets for each contiguous coherent area. We develop and test a novel method for repeat-pass InSAR-based dry-snow SWE estimation that exploits the sensitivity of the dry-snow refraction-induced InSAR phase to topographic variations. The method robustly estimates absolute SWE change at spatial resolutions of < 1 km without the need for phase unwrapping. We derive a quantitative signal model for this new SWE change estimator and identify the relevant sources of bias. The method is demonstrated using both simulated SWE distributions and a 9-year RADARSAT-2 (C-band, 5.405 GHz) spotlight-mode dataset near Inuvik, Northwest Territories (NWT), Canada. SWE results are compared to in situ snow survey measurements and estimates from ERA5 reanalysis. Our method performs well in high-relief areas, thus providing complementary coverage to passive-microwave-based SWE estimation. Further, our method has the advantage of requiring only a single wavelength band and thus can utilize existing spaceborne synthetic aperture radar systems. Article in Journal/Newspaper glacier* Inuvik Northwest Territories The Cryosphere Niedersächsisches Online-Archiv NOA Northwest Territories Canada Inuvik ENVELOPE(-133.610,-133.610,68.341,68.341) The Cryosphere 16 4 1497 1521 |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Eppler, Jayson Rabus, Bernhard Morse, Peter Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
topic_facet |
article Verlagsveröffentlichung |
description |
Area-based measurements of snow water equivalent (SWE) are important for understanding earth system processes such as glacier mass balance, winter hydrological storage in drainage basins, and ground thermal regimes. Remote sensing techniques are ideally suited for wide-scale area-based mapping with the most commonly used technique to measure SWE being passive microwave, which is limited to coarse spatial resolutions of 25 km or greater and to areas without significant topographic variation. Passive microwave also has a negative bias for large SWE. Another method is repeat-pass synthetic aperture radar interferometry (InSAR) that allows measurement of SWE change at much higher spatial resolution. However, it has not been widely adopted because (1) the phase unwrapping problem has not been robustly addressed, especially for interferograms with poor coherence, and (2) SWE change maps scaled directly from repeat-pass interferograms are not an absolute measurement but contain unknown offsets for each contiguous coherent area. We develop and test a novel method for repeat-pass InSAR-based dry-snow SWE estimation that exploits the sensitivity of the dry-snow refraction-induced InSAR phase to topographic variations. The method robustly estimates absolute SWE change at spatial resolutions of < 1 km without the need for phase unwrapping. We derive a quantitative signal model for this new SWE change estimator and identify the relevant sources of bias. The method is demonstrated using both simulated SWE distributions and a 9-year RADARSAT-2 (C-band, 5.405 GHz) spotlight-mode dataset near Inuvik, Northwest Territories (NWT), Canada. SWE results are compared to in situ snow survey measurements and estimates from ERA5 reanalysis. Our method performs well in high-relief areas, thus providing complementary coverage to passive-microwave-based SWE estimation. Further, our method has the advantage of requiring only a single wavelength band and thus can utilize existing spaceborne synthetic aperture radar systems. |
format |
Article in Journal/Newspaper |
author |
Eppler, Jayson Rabus, Bernhard Morse, Peter |
author_facet |
Eppler, Jayson Rabus, Bernhard Morse, Peter |
author_sort |
Eppler, Jayson |
title |
Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
title_short |
Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
title_full |
Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
title_fullStr |
Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
title_full_unstemmed |
Snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (InSAR) phase variations |
title_sort |
snow water equivalent change mapping from slope-correlated synthetic aperture radar interferometry (insar) phase variations |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-1497-2022 https://noa.gwlb.de/receive/cop_mods_00060775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00060351/tc-16-1497-2022.pdf https://tc.copernicus.org/articles/16/1497/2022/tc-16-1497-2022.pdf |
long_lat |
ENVELOPE(-133.610,-133.610,68.341,68.341) |
geographic |
Northwest Territories Canada Inuvik |
geographic_facet |
Northwest Territories Canada Inuvik |
genre |
glacier* Inuvik Northwest Territories The Cryosphere |
genre_facet |
glacier* Inuvik Northwest Territories The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-16-1497-2022 https://noa.gwlb.de/receive/cop_mods_00060775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00060351/tc-16-1497-2022.pdf https://tc.copernicus.org/articles/16/1497/2022/tc-16-1497-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-16-1497-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
4 |
container_start_page |
1497 |
op_container_end_page |
1521 |
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1766010476194430976 |