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ARS Home » Research » Publications at this Location » Publication #108419


item Njoku, Eni
item Koike, Toshio
item Jackson, Thomas
item Paloscia, Simonetta

Submitted to: Microwave Radiometry and Remote Sensing of the Earths Surface & Atmosphere
Publication Type: Book / Chapter
Publication Acceptance Date: 3/1/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: None.

Technical Abstract: The potential and problems of soil moisture sensing using the Advanced Microwave Scanning Radiometer (AMSR) are described. AMSR will be the first spaceborne radiometer since the Nimbus-7 SMMR to include a frequency at C-band (6.9 GHz). The ability to penetrate vegetation, and to sense deeper in the soil, increases with wavelength. The AMSR is thus expected to have a abetter soil moisture sensing capability than the DMSP SSM/I or TRMM Microwave Imager (TMI) instruments which have lowest frequencies of 19.35 and 10.7 GHz, respectively. The spatial resolution of the AMSR at 6.9 GHz is approximately 60 km, a factor of two better than the SMMR. While not optimal for soil moisture sensing, the AMSR should provide useful information over low-vegetated areas and will serve as a valuable precursor to future proposed L-band soil moisture sensors. Vegetation and snow cover, frozen ground, topography, open water, and footprint heterogeneity are factors that must be considered in estimating soil moisture. Thus, ancillary data that can provide information on surface characteristics will be useful in improving the retrievals. Descriptions and preliminary tests of different soil moisture retrieval approaches are discussed here. Experiments using surface measurements, airborne sensors, and satellite data are planned for continued development of the retrieval algorithms and for validation of the derived soil moisture products after launch.