Measurement of scattering coefficients of soil by Ka-band polarimetric scatterometer-Dependence on soil moisture content and surface roughness

To clarify the scattering characteristics of the ground surface for Ka band electromagnetic waves, which is necessary for evaluation of the effect of the Ka band rain radar on board the Global Precipitation Measurement Mission core satellite, the dependence of the normalized radar cross section (backscattering coefficient) σ0 of the soil on the surface roughness and the water content in the soil was measured with a Ka band polarimetric scatterometer. The results show that the dependence of the backscatter coefficient σ0 on the surface roughness, the moisture sensitivity, and the angle of incidence is obtained for the Ka band waves. For an angle of incidence of 10°,σ0 does not depend much on the surface roughness and increases in proportion to the water content. σ0 is calculated by the theoretical equation and the empirical equation, and is found accurate by comparison with the experiment. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(2): 1– 11, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20339