Active-layer thickness estimation from X-band SAR backscatter intensity
The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference ve...
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ftdoajarticles:oai:doaj.org/article:4fba0cbe3c8b4c4da6417ae4bd31e6ec 2023-05-15T13:03:09+02:00 Active-layer thickness estimation from X-band SAR backscatter intensity B. Widhalm A. Bartsch M. Leibman A. Khomutov 2017-02-01T00:00:00Z https://doi.org/10.5194/tc-11-483-2017 https://doaj.org/article/4fba0cbe3c8b4c4da6417ae4bd31e6ec EN eng Copernicus Publications http://www.the-cryosphere.net/11/483/2017/tc-11-483-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-483-2017 https://doaj.org/article/4fba0cbe3c8b4c4da6417ae4bd31e6ec The Cryosphere, Vol 11, Iss 1, Pp 483-496 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-483-2017 2022-12-31T16:00:20Z The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference vegetation index (NDVI) obtained from optical satellite data is used as a proxy. The applicability has been demonstrated mostly for shallow depths of active-layer thickness (ALT) below approximately 70 cm. Some permafrost areas including central Yamal are, however, characterized by larger ALT. Surface properties including vegetation structure are also represented by microwave backscatter intensity. So far, the potential of such data for estimating ALT has not been explored. We therefore investigated the relationship between ALT and X-band synthetic aperture radar (SAR) backscatter of TerraSAR-X (averages for 10 × 10 m window) in order to examine the possibility of delineating ALT with continuous and larger spatial coverage in this area and compare it to the already-established method of using NDVI from Landsat (30 m). Our results show that the mutual dependency of ALT and TerraSAR-X backscatter on land cover types suggests a connection of both parameters. A range of 5 dB can be observed for an ALT range of 100 cm (40–140 cm), and an R 2 of 0.66 has been determined over the calibration sites. An increase of ALT with increasing backscatter can be determined. The root mean square error (RMSE) over a comparably heterogeneous validation site with maximum ALT of > 150 cm is 20 cm. Deviations are larger for measurement locations with mixed vegetation types (especially partial coverage by cryptogam crust) with respect to the spatial resolution of the satellite data. Article in Journal/Newspaper Active layer thickness permafrost The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 11 1 483 496 |
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Directory of Open Access Journals: DOAJ Articles |
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language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
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Environmental sciences GE1-350 Geology QE1-996.5 B. Widhalm A. Bartsch M. Leibman A. Khomutov Active-layer thickness estimation from X-band SAR backscatter intensity |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference vegetation index (NDVI) obtained from optical satellite data is used as a proxy. The applicability has been demonstrated mostly for shallow depths of active-layer thickness (ALT) below approximately 70 cm. Some permafrost areas including central Yamal are, however, characterized by larger ALT. Surface properties including vegetation structure are also represented by microwave backscatter intensity. So far, the potential of such data for estimating ALT has not been explored. We therefore investigated the relationship between ALT and X-band synthetic aperture radar (SAR) backscatter of TerraSAR-X (averages for 10 × 10 m window) in order to examine the possibility of delineating ALT with continuous and larger spatial coverage in this area and compare it to the already-established method of using NDVI from Landsat (30 m). Our results show that the mutual dependency of ALT and TerraSAR-X backscatter on land cover types suggests a connection of both parameters. A range of 5 dB can be observed for an ALT range of 100 cm (40–140 cm), and an R 2 of 0.66 has been determined over the calibration sites. An increase of ALT with increasing backscatter can be determined. The root mean square error (RMSE) over a comparably heterogeneous validation site with maximum ALT of > 150 cm is 20 cm. Deviations are larger for measurement locations with mixed vegetation types (especially partial coverage by cryptogam crust) with respect to the spatial resolution of the satellite data. |
format |
Article in Journal/Newspaper |
author |
B. Widhalm A. Bartsch M. Leibman A. Khomutov |
author_facet |
B. Widhalm A. Bartsch M. Leibman A. Khomutov |
author_sort |
B. Widhalm |
title |
Active-layer thickness estimation from X-band SAR backscatter intensity |
title_short |
Active-layer thickness estimation from X-band SAR backscatter intensity |
title_full |
Active-layer thickness estimation from X-band SAR backscatter intensity |
title_fullStr |
Active-layer thickness estimation from X-band SAR backscatter intensity |
title_full_unstemmed |
Active-layer thickness estimation from X-band SAR backscatter intensity |
title_sort |
active-layer thickness estimation from x-band sar backscatter intensity |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-483-2017 https://doaj.org/article/4fba0cbe3c8b4c4da6417ae4bd31e6ec |
genre |
Active layer thickness permafrost The Cryosphere |
genre_facet |
Active layer thickness permafrost The Cryosphere |
op_source |
The Cryosphere, Vol 11, Iss 1, Pp 483-496 (2017) |
op_relation |
http://www.the-cryosphere.net/11/483/2017/tc-11-483-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-483-2017 https://doaj.org/article/4fba0cbe3c8b4c4da6417ae4bd31e6ec |
op_doi |
https://doi.org/10.5194/tc-11-483-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
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1 |
container_start_page |
483 |
op_container_end_page |
496 |
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