Inversion algorithm for soil moisture retrieval from polarimetric backscattering coefficients of vegetation canopies

Abstract

This paper presents soil moisture retrieval from measured Polarimetrie backscattering coefficients of a vegetated surface. Based on the analysis of the quite complicate firstorder radiative transfer scattering model for vegetated surfaces, a simplified scattering model is proposed for an inversion algorithm. Extraction of the surface-scatter component from the total scattering of a vegetation canopy is addressed using the simplified model, and also using the three-component decomposition technique. The backscattering coefficients are measured with a Polarimetrie Lband scatterometer during two months as well as the biomasses, leaf moisture contents, and soil moisture contents. Then the measurement data are used to estimate the model parameters for w-, hh-, and vh-polarizations. The scattering model for tall-grass-covered surfaces is inverted to retrieve the soil moisture content from the measurements using a genetic algorithm. The retrieved soil moisture contents agree quite well with the in-situ measured soil moisture data. ©2008 IEEE.