L-band emission of rough surfaces: Comparison between experimental data and different modeling approaches

In this paper we present a study of a numerical modeling approach based on the Finite Element Method (FEM) for the prediction of rough surface emission at L-band, including a comparison with other modeling approaches and experimental data. The numerical approach relies on the use of ANSYS´ numerical computation software HFSS (High Frequency Structure Simulator), which in turn solves Maxwell´s equations directly using the Finite Element Method. It is useful in the context of the SMOS (Soil Moisture and Ocean Salinity) mission since it can be extended to model the scattering and emission of heterogeneous media including complex multilayer systems such as the radiometric L-band emission of soil and litter layers in forests. In this paper we firstly validate the approach by comparing predictions of rough surface scattering against the Method of Moments (MoM). Secondly we study the accuracy of the numerical approach by comparing results of rough surface emissivity against measurements and predictions of the Advanced Integral Equation Method (AIEM).