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| Titel |
Interferometric swath processing of Cryosat data for glacial ice topography |
| VerfasserIn |
L. Gray, D. Burgess, L. Copland, R. Cullen, N. Galin, R. Hawley, V. Helm |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 6 ; Nr. 7, no. 6 (2013-12-12), S.1857-1867 |
| Datensatznummer |
250085187
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| Publikation (Nr.) |
 copernicus.org/tc-7-1857-2013.pdf |
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| Zusammenfassung |
| We have derived digital elevation models (DEMs) over the western part of the
Devon Ice Cap in Nunavut, Canada, using "swath processing" of interferometric
data collected by Cryosat between February 2011 and January 2012. With the standard
ESA (European Space Agency) SARIn (synthetic aperture radar interferometry) level 2 (L2) data product, the interferometric mode is used to
map the cross-track position and elevation of the
"point-of-closest-approach" (POCA) in sloping glacial terrain. However, in
this work we explore the extent to which the phase of the returns in the
intermediate L1b product can also be used to map the heights of time-delayed
footprints beyond the POCA. We show that there is a range of average
cross-track slopes (~ 0.5 to ~ 2°) for which the returns will be dominated by those beneath the
satellite in the main beam of the antenna so that the resulting
interferometric phase allows mapping of heights in the delayed range window
beyond the POCA. In this way a swath of elevation data is mapped, allowing
the creation of DEMs from a sequence of L1b SARIn
Cryosat data takes. Comparison of the Devon results with airborne scanning
laser data showed a mean difference of order 1 m with a standard
deviation of about 1 m. The limitations of swath processing, which
generates almost 2 orders of magnitude more data than traditional radar
altimetry, are explored through simulation, and the strengths and weaknesses
of the technique are discussed. |
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