The method for soil moisture inversion based on ground-based scattering measurement

摘要

With the ENVISAT-ASAR Alternating Polarisation mode and the parameter sets of HJ-1C-SAR as the research foundation, using the measurement data by multi-wave bands and multi-polarization ground-based scatterometer, the paper studies an inversion method of bare-surface soil moisture. The studies simultaneously consider the influence which include root-mean-square height S and correlation length L in this method, and combine the two roughness parameters, expressed as a combination of roughness Zs. Using Integral Equation Model (IEM) to analysis the relationship between Zs in different incident angles and the difference of the backscattering coefficients under two wavelengths, establishes the multinomial semi-empirical model for soil moisture inversion under different angles. The model's validation is conformed by the ground-based scattering datas, the results show that, for the medium and low roughness of the bare surface, the error is smaller than 15 percent between inversion value with the model and the measured soil moisture.