Rough Surface Statistics Iem Method

The problem of EM scattering from rough surfaces has been the focus of many scientists for nearly half a century and led to a tenet of mathematic models. In 1990s, A. K. Fung et al proposed a integrated equation model (EEM). The model can be used in surfaces with a large scale of roughness in great efficiency.The statistical integral equation model (SIEM) improved some disadvantage of IEM. It treats the local coordinates and Fresnel reflection coefficients statistically. In addition, it incorporates more rigorously the shadowing function in the Kirchhoff and complementary fields through a careful treatment of the Poggio & Miller equation. In calculating the incoherent scattered Kirchhoff power, for a Gaussian rough surface, the joint probability density function of the surface unit normals at two different surface points is rigorously applied, and decomposition of its covariance matrix into uncorrelated term and fully correlated terms of different types enables a drastic simplification of the required calculations.