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Different ERS altimeter measurements between ascending and descending tracks caused by wind induced features over ice sheets
Author(s) -
Legresy Benoît,
Remy Frédérique,
Schaeffer Philippe
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900531
Subject(s) - altimeter , geology , radar altimeter , scatterometer , snowpack , remote sensing , radar , geodesy , satellite , snow , wind speed , geomorphology , telecommunications , oceanography , aerospace engineering , computer science , engineering
The ERS1 satellite provides a high‐resolution radar altimeter measurement up to 81.5° latitude for polar cap studies. Here we examine one particular effect of the interaction between the radar wave and the snowpack surface on height measurements. Measurements from ascending and descending tracks show systematic differences as large as 1 m. Such an artifact to be removed if it can be estimated. The difference appears to be related to the way the altimeter perceives wind‐induced sculpting of the snowpack. Differences in the volume echo weight between ascending and descending passes appear to be the explanation. Seasat scatterometer allowed us to estimate independently the signal that could be inferred by wind features. Our results yield a map of the effect of wind on radar altimetric measurement. Finally, we consider the possibility of long‐term variations in altimeter measurements caused by climatic changes.