Validation of left-right method for scattering by a rough surface

The method of left-right splitting is studied for the calculation of electr omagnetic fields on a finite, perfectly conducting, corrugated rough surfac e. Surface currents are evaluated for TE and TM polarizations, both on the rough surface and on an extended surface with a rough patch, and these are compared with results from a finite element time-domain calculation. Very g ood agreement is obtained with one or two terms in the series. The effect o f surface truncation is studied for the two polarizations, together with th e reflected and transmitted components to the left and right of the rough s urface patch, and the TM polarization is found to be relatively insensitive to the surface truncation.