Abstract
Antarctic ice sheets play an important role in global sea-levels
and climate changes. Snowmelt information with high spatial resolution
on the surface of ice sheets is of great significance to the study of
global climate change. Currently, the spatial resolution of snowmelt
detection results based on low-frequency data from microwave radiometers
is low, and accurate freeze-thaw changes cannot be obtained. The spatial
resolution of Advanced Microwave Scanning Radiometer-2(AMSR-2)89GHz data
is at least twice that of other microwave channels, but vulnerable to
atmospheric water vapour. This paper proposes a method to detect
snowmelt on the Antarctic ice sheet based on 89GHz data. First,
according to the stable relationship of the polarization ratio(PR)of
89GHz and 36GHz data under clear, cloudless weather, the affected 89GHz
data were selected. Then, the functional relationship between 36 GHz
data and the unaffected 89 GHz data was obtained. Finally, the modified
89 GHz data were applied to snowmelt detection on the Antarctic ice
sheet. The average detection accuracy of this method in six automatic
weather stations was 91%, while the average detection accuracy of the
cross-polarized gradient ratio algorithm(XPGR)was 74%. The experimental
results show that the modified 89GHz data have a high accuracy in
detecting snowmelt in Antarctic ice sheets.
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