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Titel |
Waveform classification of airborne synthetic aperture radar altimeter over Arctic sea ice |
VerfasserIn |
M. Zygmuntowska, K. Khvorostovsky, V. Helm, S. Sandven |
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. 4 ; Nr. 7, no. 4 (2013-08-19), S.1315-1324 |
Datensatznummer |
250085149
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Publikation (Nr.) |
copernicus.org/tc-7-1315-2013.pdf |
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Zusammenfassung |
Sea ice thickness is one of the most sensitive variables in the Arctic
climate system. In order to quantify changes in sea ice thickness, CryoSat-2
was launched in 2010 carrying a Ku-band radar altimeter (SIRAL) designed to
measure sea ice freeboard with a few centimeters accuracy. The instrument
uses the synthetic aperture radar technique providing signals with
a resolution of about 300 m along track. In this study, airborne Ku-band
radar altimeter data over different sea ice types have been analyzed. A set of
parameters has been defined to characterize the differences in strength and
width of the returned power waveforms. With a Bayesian-based method, it is
possible to classify about 80% of the waveforms from three parameters:
maximum of the returned power waveform, the trailing edge width and pulse
peakiness. Furthermore, the maximum of the power waveform can be used to
reduce the number of false detections of leads, compared to the widely used
pulse peakiness parameter. For the pulse peakiness the false classification
rate is 12.6% while for the power maximum it is reduced to 6.5%. The
ability to distinguish between different ice types and leads allows us to
improve the freeboard retrieval and the conversion from freeboard into sea
ice thickness, where surface type dependent values for the sea ice density
and snow load can be used. |
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