The statistical inversion algorithm of bare surface soil moisture for the AMSR using C-band IEM simulated emissivity

Based on the bistatic scattering theory a simulated database of bare soil surface emissivity with dual polarization is found for the configuration of AMSR using the Integral Equation Method (IEM). Parameters including soil moisture, correlation length and RMS height are mainly considered to evaluate the signature of the bare soil surface emissivity. Analysis has been done to investigate the relationship between the emissivity and the parameters. The results show that the influence of soil surface moisture and roughness parameters on the emissivity is quite complex. It is difficult to separate the coupled influence of the moisture and roughness factors through only statistical processing. An algorithm for estimation of soil surface moisture with AMSR at C-band is developed based on the method to extract a pair of functions corresponding to vertical and horizontal polarization and depending only on dielectric constant and incident angle. There is a good linear relation between the combinations of the extracted functions and the dual polarized emissivity. Hence, if we obtain the measurements of the dual polarized emissivity of a pixel the soil surface moisture can be estimated from the dielectric constant calculated from the statistical relations.