COUPLING THE TEMPERATURE AND MINERALOGY DEPENDABLE SOIL DIELECTRIC MODEL AND A NUMERICAL MODEL TO COMPUTE SCATTERING COEFFICIENT OF COMPLEX MULTILAYER SOIL STRUCTURES
Résumé
In this paper we present a study of a three dimensional (3D) numerical modeling approach based on the Finite Element Method (FEM) for the prediction of the bistatic coefficient of rough soil covered by a litter layer at L-band, including a comparison with another modeling approach. 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. The computation of bistatic coefficient of ground structures need to introduce to the numerical model the dielectric properties of soil. We use the TMD SDM (Temperature and Mineralogy Dependable Soil Dielectric Model) which is a dielectric mixing model to predict the permittivity of the soil (V. Mironov et al.). It is useful in the context of the SMOS (Soil Moisture and Ocean Salinity) or SMAP (Soil Moisture Active & Passive) mission since our numerical approach can be extended to model the scattering and emission of heterogeneous media including complex multilayer systems such as the radiometric L-band emission or the bistatic coefficient of soil and litter layers in forests. In this paper we validate the approach by comparing predictions of rough surface scattering against the Method of Moments (MoM).