Simulation and Analysis of Backscattering Characteristics of Soil with Row Structure

In order to retrieve soil moisture through active microwave methods, the quantitative relation between the backscattering coefficients and soil moisture should be established. The dependence of backscattering coefficients on soil parameters, radar parameters and row structure parameters was analyzed by using Ulaby model. It was found that M values (the sensitivity of backscattering coefficient to azimuth angle) in different polarization modes showed as HH > VV > VH. The M value is influenced by the variation of soil moisture and surface roughness in HH polarization, but that won’t happen in VV and VH polarizations, so VV and VH polarizations are more suitable for retrieving soil moisture with row structure. The responding function is different for different incident angles, if the incident angles changes significantly in a SAR image, the effect must be considered in building inversion model of soil moisture.