Backscattering enhancement of a two-dimensional random rough surface (three-dimensional scattering) based on Monte Carlo simulations

The exact solution of scattering by a two-dimensional random rough surface (three-dimensional scattering problem) of an area of 80 square wavelengths with 4096 surface unknowns is computed, and the results show backscattering enhancement. The computation is based on a new numerical method called the sparse-matrix flat-surface iterative approach. The approach decomposes the matrix of the integral equation as a sum of a sparse matrix, a flat-surface block Toeplitz matrix, and a weak remainder that is followed by an iterative solution until convergence is achieved.