Improved numerical simulation of electromagnetic wave scattering from perfectly conducting random surfaces

A Monte Carlo simulation of electromagnetic scattering from one-dimensional perfectly conducting random surfaces is considered. Surface profiles of desired statistics are generated numerically using a standard procedure and the scattering solution for the surface samples of finite length is calculated using the method of moments. A new technique is used to reduce the effect of the edges of the finite surface samples. In this technique, the conductivities of the surface near edges are controlled by adding an appropriate tapered resistive sheet. It is shown that the accuracy at large angles of incidence, θ>50°, and the computation efficiency are improved significantly using this method, when compared to the standard tapered illumination method. Results based on this numerical approach are compared with those based on the small perturbation and physical optics approximations in their respective regions of validity