Bistatic scattering, backscattering and emissivities of randomly rough soil surfaces at L band based on numerical solutions of Maxwell equations of 3 Dimensional simulations

摘要

In this paper, we used NMM3D (Numerical Maxwell Model of 3 Dimensional simulations) to study the full wave 3 dimensional scattering of random soil surfaces. In 3D simulations, the height function z=f(x,y) of the rough surfaces vary in both two horizontal directions. Several hundreds of cases are simulated by varying incident angles, surface roughness and soil permittivities. The incident angles vary from 20° to 50°. The coherent/incoherent bistatic coefficients, backscattering coefficients, and emissivities are computed. The results are compared with empirical models and analytical methods. The backscattering coefficients are compared with measurement data and are found to be in good agreement. Based on the several hundreds of computed case, interpolation tables are made for the full range of parameters that can be directly applied to L band active and passive microwave remote sensing of soil moisture, such as the SMAP Mission and the SMOS Mission.