Evolution of Semi-empirical Approach: Modeling and Inversion

Semi-empirical models for radar scattering from vegetation are discussed in this chapter. The evolution of semi-empirical approaches from the dielectric slab model to the Water Cloud Model (WCM) and its modified forms are presented with their theoretical development. A section is dedicated to evaluating the theoretical aspect of WCM parameterization from several physical models, including Rayleigh, Generalized Rayleigh–Gans (GRG) approximations, and Single Scattering Radiative Transfer (S2RT). State-of-the-art inversion approaches are successively presented in the following sections. We have also provided program codes and evaluated model validity and comparisons for varying vegetation and soil parameters.