Altimetric observations of surface characteristics of the Antarctic ice sheet
Abstract The aim of this paper is to investigate the geophysical characteristics of the Antarctic ice sheet using radar altimetric observations. To do this, we use an altimetric waveform simulator, in situ observations, ERS-1 (European remote-sensing satellite) data and SPOT (Satellite pour l’observ...
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Cambridge University Press (CUP)
1997
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Online Access: | http://dx.doi.org/10.1017/s002214300000321x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300000321X |
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crcambridgeupr:10.1017/s002214300000321x 2024-09-30T14:26:24+00:00 Altimetric observations of surface characteristics of the Antarctic ice sheet Legrésy, Benoît Rémy, Frédérique 1997 http://dx.doi.org/10.1017/s002214300000321x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300000321X en eng Cambridge University Press (CUP) Journal of Glaciology volume 43, issue 144, page 265-275 ISSN 0022-1430 1727-5652 journal-article 1997 crcambridgeupr https://doi.org/10.1017/s002214300000321x 2024-09-11T04:03:37Z Abstract The aim of this paper is to investigate the geophysical characteristics of the Antarctic ice sheet using radar altimetric observations. To do this, we use an altimetric waveform simulator, in situ observations, ERS-1 (European remote-sensing satellite) data and SPOT (Satellite pour l’observation de la terre) images. The small-scale study takes place at Dome C, Terre Adélie, which is a relatively flat region with gentle undulations and low wind speed. Despite this, the altimetric waveform parameters (height, energy, leading edge and trailing edge) are highly noisy. The effect of undulations on the waveform parameters is found to be dominant. The combination of a subsurface signal and a rough surface produces a linear effect on the altimetric backscattering or on the trailing edge of the waveform, but a strongly non-linear effect on the leading edge of the waveform or height estimation. As a consequence, the height measurement is very sensitive to the altimeter technical or orbital characteristics and is not reproducible from one mission to another. Observations show sastrugi fields that enhance the leading edge and affect the whole waveform. Observed local backscattering changes, probably due to local variations in surface microroughness, enhance the backscattered energy and may artificially create a topographic signal. The continental-scale study shows coherent patterns. Even if both surface and subsurface components affect the altimetric observation, the large-scale signal is mostly controlled by surface backscattering variations. The surface or near-subsurface characteristics of the snowpack may then be reached by altimetric observations. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Journal of Glaciology Cambridge University Press Antarctic The Antarctic Terre Adélie ENVELOPE(139.000,139.000,-67.000,-67.000) Terre-Adélie ENVELOPE(138.991,138.991,-59.999,-59.999) Sastrugi ENVELOPE(163.683,163.683,-74.617,-74.617) Journal of Glaciology 43 144 265 275 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract The aim of this paper is to investigate the geophysical characteristics of the Antarctic ice sheet using radar altimetric observations. To do this, we use an altimetric waveform simulator, in situ observations, ERS-1 (European remote-sensing satellite) data and SPOT (Satellite pour l’observation de la terre) images. The small-scale study takes place at Dome C, Terre Adélie, which is a relatively flat region with gentle undulations and low wind speed. Despite this, the altimetric waveform parameters (height, energy, leading edge and trailing edge) are highly noisy. The effect of undulations on the waveform parameters is found to be dominant. The combination of a subsurface signal and a rough surface produces a linear effect on the altimetric backscattering or on the trailing edge of the waveform, but a strongly non-linear effect on the leading edge of the waveform or height estimation. As a consequence, the height measurement is very sensitive to the altimeter technical or orbital characteristics and is not reproducible from one mission to another. Observations show sastrugi fields that enhance the leading edge and affect the whole waveform. Observed local backscattering changes, probably due to local variations in surface microroughness, enhance the backscattered energy and may artificially create a topographic signal. The continental-scale study shows coherent patterns. Even if both surface and subsurface components affect the altimetric observation, the large-scale signal is mostly controlled by surface backscattering variations. The surface or near-subsurface characteristics of the snowpack may then be reached by altimetric observations. |
format |
Article in Journal/Newspaper |
author |
Legrésy, Benoît Rémy, Frédérique |
spellingShingle |
Legrésy, Benoît Rémy, Frédérique Altimetric observations of surface characteristics of the Antarctic ice sheet |
author_facet |
Legrésy, Benoît Rémy, Frédérique |
author_sort |
Legrésy, Benoît |
title |
Altimetric observations of surface characteristics of the Antarctic ice sheet |
title_short |
Altimetric observations of surface characteristics of the Antarctic ice sheet |
title_full |
Altimetric observations of surface characteristics of the Antarctic ice sheet |
title_fullStr |
Altimetric observations of surface characteristics of the Antarctic ice sheet |
title_full_unstemmed |
Altimetric observations of surface characteristics of the Antarctic ice sheet |
title_sort |
altimetric observations of surface characteristics of the antarctic ice sheet |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s002214300000321x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214300000321X |
long_lat |
ENVELOPE(139.000,139.000,-67.000,-67.000) ENVELOPE(138.991,138.991,-59.999,-59.999) ENVELOPE(163.683,163.683,-74.617,-74.617) |
geographic |
Antarctic The Antarctic Terre Adélie Terre-Adélie Sastrugi |
geographic_facet |
Antarctic The Antarctic Terre Adélie Terre-Adélie Sastrugi |
genre |
Antarc* Antarctic Ice Sheet Journal of Glaciology |
genre_facet |
Antarc* Antarctic Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 43, issue 144, page 265-275 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s002214300000321x |
container_title |
Journal of Glaciology |
container_volume |
43 |
container_issue |
144 |
container_start_page |
265 |
op_container_end_page |
275 |
_version_ |
1811646755468476416 |