Publication Date:
2012-11-02
Description:
Soil moisture is one of the important input variables in hydrological and water erosion models. The extraction of information on near surface soil moisture from Synthetic Aperture Radar (SAR) is well established mostly for flat terrain and using low incidence angle single polarization data. The ENVISAT Advanced Synthetic Aperture Radar (ASAR) data available in multiple incidence angles and alternate polarization modes were investigated in this study for soil moisture estimation in sloping terrain. The test site was Sitla Rao watershed in the Lesser Himalayas of northern India. Empirical models were developed to estimate near surface soil moisture in bare agricultural fields using alternate polarisation ASAR data. Both soil moisture and surface roughness field measurements were performed during the satellite passes. Backscatter from medium incidence angle (IS-4) and VV polarization signal is correlated better with volumetric soil moisture content compared to other incidence angles. The model parameters were further improved and soil moisture estimation was refined by combining medium incidence angle (IS4) VH polarization response as another variable along with VV polarization response. The effect of slope on the radar backscatter was minimized by incorporating local incidence angles derived from an ASTER DEM. Copyright © 2012 John Wiley & Sons, Ltd.
Print ISSN:
0885-6087
Electronic ISSN:
1099-1085
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
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