Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation
Definite surface topography of ice provides fundamental information for most glaciologists to study climate change. However, the topography at the marginal region of ice sheets exhibits noticeable dynamical changes from fast flow velocity and large thinning rates; thus, it is difficult to determine...
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ftdoajarticles:oai:doaj.org/article:6610ea2e3a26409aa9bdf40debc6c020 2023-05-15T13:34:48+02:00 Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation Seung Hee Kim Duk-jin Kim 2017-02-01T00:00:00Z https://doi.org/10.3390/rs9020176 https://doaj.org/article/6610ea2e3a26409aa9bdf40debc6c020 EN eng MDPI AG http://www.mdpi.com/2072-4292/9/2/176 https://doaj.org/toc/2072-4292 2072-4292 doi:10.3390/rs9020176 https://doaj.org/article/6610ea2e3a26409aa9bdf40debc6c020 Remote Sensing, Vol 9, Iss 2, p 176 (2017) TanDEM-X CryoSat-2 digital elevation model Antarctica ice sheet Science Q article 2017 ftdoajarticles https://doi.org/10.3390/rs9020176 2022-12-31T11:26:11Z Definite surface topography of ice provides fundamental information for most glaciologists to study climate change. However, the topography at the marginal region of ice sheets exhibits noticeable dynamical changes from fast flow velocity and large thinning rates; thus, it is difficult to determine instantaneous topography. In this study, the surface topography of the marginal region of Thwaites Glacier in the Amundsen Sector of West Antarctica, where ice melting and thinning are prevailing, is extracted using TanDEM-X interferometry in combination with data from the near-coincident CryoSat-2 radar altimeter. The absolute height offset, which has been a persistent problem in applying the interferometry technique for generating DEMs, is determined by linear least-squares fitting between the uncorrected TanDEM-X heights and reliable reference heights from CryoSat-2. The reliable heights are rigorously selected at locations of high normalized cross-correlation and low RMS heights between segments of data points. The generated digital elevation model with the resolved absolute height offset is assessed with airborne laser altimeter data from the Operation IceBridge that were acquired five months after TanDEM-X and show high correlation with biases of 3.19 m and −4.31 m at the grounding zone and over the ice sheet surface, respectively. For practical application of the generated DEM, grounding line estimation assuming hydrostatic equilibrium was carried out, and the feasibility was seen through comparison with the previous grounding line. Finally, it is expected that the combination of interferometry and altimetery with similar datasets can be applied at regions even with a lack of ground control points. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Thwaites Glacier West Antarctica Directory of Open Access Journals: DOAJ Articles West Antarctica Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) Remote Sensing 9 2 176 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
TanDEM-X CryoSat-2 digital elevation model Antarctica ice sheet Science Q |
spellingShingle |
TanDEM-X CryoSat-2 digital elevation model Antarctica ice sheet Science Q Seung Hee Kim Duk-jin Kim Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
topic_facet |
TanDEM-X CryoSat-2 digital elevation model Antarctica ice sheet Science Q |
description |
Definite surface topography of ice provides fundamental information for most glaciologists to study climate change. However, the topography at the marginal region of ice sheets exhibits noticeable dynamical changes from fast flow velocity and large thinning rates; thus, it is difficult to determine instantaneous topography. In this study, the surface topography of the marginal region of Thwaites Glacier in the Amundsen Sector of West Antarctica, where ice melting and thinning are prevailing, is extracted using TanDEM-X interferometry in combination with data from the near-coincident CryoSat-2 radar altimeter. The absolute height offset, which has been a persistent problem in applying the interferometry technique for generating DEMs, is determined by linear least-squares fitting between the uncorrected TanDEM-X heights and reliable reference heights from CryoSat-2. The reliable heights are rigorously selected at locations of high normalized cross-correlation and low RMS heights between segments of data points. The generated digital elevation model with the resolved absolute height offset is assessed with airborne laser altimeter data from the Operation IceBridge that were acquired five months after TanDEM-X and show high correlation with biases of 3.19 m and −4.31 m at the grounding zone and over the ice sheet surface, respectively. For practical application of the generated DEM, grounding line estimation assuming hydrostatic equilibrium was carried out, and the feasibility was seen through comparison with the previous grounding line. Finally, it is expected that the combination of interferometry and altimetery with similar datasets can be applied at regions even with a lack of ground control points. |
format |
Article in Journal/Newspaper |
author |
Seung Hee Kim Duk-jin Kim |
author_facet |
Seung Hee Kim Duk-jin Kim |
author_sort |
Seung Hee Kim |
title |
Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
title_short |
Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
title_full |
Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
title_fullStr |
Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
title_full_unstemmed |
Combined Usage of TanDEM-X and CryoSat-2 for Generating a High Resolution Digital Elevation Model of Fast Moving Ice Stream and Its Application in Grounding Line Estimation |
title_sort |
combined usage of tandem-x and cryosat-2 for generating a high resolution digital elevation model of fast moving ice stream and its application in grounding line estimation |
publisher |
MDPI AG |
publishDate |
2017 |
url |
https://doi.org/10.3390/rs9020176 https://doaj.org/article/6610ea2e3a26409aa9bdf40debc6c020 |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
West Antarctica Thwaites Glacier |
geographic_facet |
West Antarctica Thwaites Glacier |
genre |
Antarc* Antarctica Ice Sheet Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet Thwaites Glacier West Antarctica |
op_source |
Remote Sensing, Vol 9, Iss 2, p 176 (2017) |
op_relation |
http://www.mdpi.com/2072-4292/9/2/176 https://doaj.org/toc/2072-4292 2072-4292 doi:10.3390/rs9020176 https://doaj.org/article/6610ea2e3a26409aa9bdf40debc6c020 |
op_doi |
https://doi.org/10.3390/rs9020176 |
container_title |
Remote Sensing |
container_volume |
9 |
container_issue |
2 |
container_start_page |
176 |
_version_ |
1766057629451288576 |