MONTE-CARLO SIMULATIONS OF LARGE-SCALE PROBLEMS OF RANDOM ROUGH-SURFACE SCATTERING AND APPLICATIONS TO GRAZING-INCIDENCE WITH THE BMIA/CANONICAL GRID METHOD

Scattering of a TE incident wave from a perfectly conducting one-dimensional random rough surface is studied with the banded matrix iterative approach/canonical grid (BMIA/CAG) method, The BMIA/CAG is an improvement over the previous BMIA. The key idea of BMIA/CAG is that outside the near-held interaction, the rest of the interactions can be translated to a canonical grid by Taylor series expansion, The use of a flat surface as a canonical grid for a rough surface facilitates the use of the fast Fourier transform for nonnear field interaction, The method can be used for Monte-Carlo simulations of random rough surface problems with a large surface length including all the coherent wave interactions within the entire surface, We illustrate results up to a surface length of 2500 wavelengths with 25 000 surface unknowns. The method is also applied to study scattering from random rough surfaces at near-grazing incidence, The numerical examples illustrate the importance of using a large surface length for some backscattering problems.