Radar Remote Sensing of Soil Moisture and SurfaceRoughness for Vegetated Surfaces

Abstract

This paper presents radar remote sensing of soil moisture and surface roughness forvegetated surfaces. A precise volume scattering model for a vegetated surface is derived based on the first-order radiative transfer technique. At first, the scattering mechanisms of the scattering model are analyzedfor various conditions of the vegetation canopies. Then, the scattering model is simplified step by step fordeveloping an appropriate inversion algorithm. For verifying the scattering model and the inversionalgorithm, the polarimetric backscattering coefficients at 1.85 GHz, as well as the ground truth data, of atall-grass field are measured for various soil moisture conditions. The genetic algorithm is employed in theinversion algorithm for retrieving soil moisture and surface roughness from the radar measurements. It isfound that the scattering model agrees quite well with the measurements. It is also found that the retrievedsoil moisture and surface roughness parameters agree well with the field-measured ground truth data.