A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods
Digital elevation models (DEMs) of the whole of Antarctica have been derived, previously, from satellite radar altimetry (SRA) and limited terrestrial data. Near the ice sheet margins and in other areas of steep relief the SRA data tend to have relatively poor coverage and accuracy. To remedy this a...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:62a1bd298f354db4bf13bc306414ca12 2023-05-15T13:37:01+02:00 A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods J. L. Bamber J. L. Gomez-Dans J. A. Griggs 2009-05-01 http://www.the-cryosphere.net/3/101/2009/tc-3-101-2009.pdf https://doaj.org/article/62a1bd298f354db4bf13bc306414ca12 en eng Copernicus Publications 1994-0416 1994-0424 http://www.the-cryosphere.net/3/101/2009/tc-3-101-2009.pdf https://doaj.org/article/62a1bd298f354db4bf13bc306414ca12 undefined The Cryosphere, Vol 3, Iss 1, Pp 101-111 (2009) geo info Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2009 fttriple 2023-01-22T19:34:56Z Digital elevation models (DEMs) of the whole of Antarctica have been derived, previously, from satellite radar altimetry (SRA) and limited terrestrial data. Near the ice sheet margins and in other areas of steep relief the SRA data tend to have relatively poor coverage and accuracy. To remedy this and to extend the coverage beyond the latitudinal limit of the SRA missions (81.5° S) we have combined laser altimeter measurements from the Geosciences Laser Altimeter System onboard ICESat with SRA data from the geodetic phase of the ERS-1 satellite mission. The former provide decimetre vertical accuracy but with poor spatial coverage. The latter have excellent spatial coverage but a poorer vertical accuracy. By combining the radar and laser data using an optimal approach we have maximised the vertical accuracy and spatial resolution of the DEM and minimised the number of grid cells with an interpolated elevation estimate. We assessed the optimum resolution for producing a DEM based on a trade-off between resolution and interpolated cells, which was found to be 1 km. This resulted in just under 32% of grid cells having an interpolated value. The accuracy of the final DEM was assessed using a suite of independent airborne altimeter data and used to produce an error map. The RMS error in the new DEM was found to be roughly half that of the best previous 5 km resolution, SRA-derived DEM, with marked improvements in the steeper marginal and mountainous areas and between 81.5 and 86° S. The DEM contains a wealth of information related to ice flow. This is particularly apparent for the two largest ice shelves – the Filchner-Ronne and Ross – where the surface expression of flow of ice streams and outlet glaciers can be traced from the grounding line to the calving front. The surface expression of subglacial lakes and other basal features are also illustrated. We also use the DEM to derive new estimates of balance velocities and ice divide locations. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere Unknown Antarctic The Antarctic |
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geo info J. L. Bamber J. L. Gomez-Dans J. A. Griggs A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
topic_facet |
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description |
Digital elevation models (DEMs) of the whole of Antarctica have been derived, previously, from satellite radar altimetry (SRA) and limited terrestrial data. Near the ice sheet margins and in other areas of steep relief the SRA data tend to have relatively poor coverage and accuracy. To remedy this and to extend the coverage beyond the latitudinal limit of the SRA missions (81.5° S) we have combined laser altimeter measurements from the Geosciences Laser Altimeter System onboard ICESat with SRA data from the geodetic phase of the ERS-1 satellite mission. The former provide decimetre vertical accuracy but with poor spatial coverage. The latter have excellent spatial coverage but a poorer vertical accuracy. By combining the radar and laser data using an optimal approach we have maximised the vertical accuracy and spatial resolution of the DEM and minimised the number of grid cells with an interpolated elevation estimate. We assessed the optimum resolution for producing a DEM based on a trade-off between resolution and interpolated cells, which was found to be 1 km. This resulted in just under 32% of grid cells having an interpolated value. The accuracy of the final DEM was assessed using a suite of independent airborne altimeter data and used to produce an error map. The RMS error in the new DEM was found to be roughly half that of the best previous 5 km resolution, SRA-derived DEM, with marked improvements in the steeper marginal and mountainous areas and between 81.5 and 86° S. The DEM contains a wealth of information related to ice flow. This is particularly apparent for the two largest ice shelves – the Filchner-Ronne and Ross – where the surface expression of flow of ice streams and outlet glaciers can be traced from the grounding line to the calving front. The surface expression of subglacial lakes and other basal features are also illustrated. We also use the DEM to derive new estimates of balance velocities and ice divide locations. |
format |
Article in Journal/Newspaper |
author |
J. L. Bamber J. L. Gomez-Dans J. A. Griggs |
author_facet |
J. L. Bamber J. L. Gomez-Dans J. A. Griggs |
author_sort |
J. L. Bamber |
title |
A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
title_short |
A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
title_full |
A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
title_fullStr |
A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
title_full_unstemmed |
A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods |
title_sort |
new 1 km digital elevation model of the antarctic derived from combined satellite radar and laser data – part 1: data and methods |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
http://www.the-cryosphere.net/3/101/2009/tc-3-101-2009.pdf https://doaj.org/article/62a1bd298f354db4bf13bc306414ca12 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 3, Iss 1, Pp 101-111 (2009) |
op_relation |
1994-0416 1994-0424 http://www.the-cryosphere.net/3/101/2009/tc-3-101-2009.pdf https://doaj.org/article/62a1bd298f354db4bf13bc306414ca12 |
op_rights |
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1766087017213460480 |