FULL-WAVE SINGLE AND DOUBLE SCATTER FROM ROUGH SURFACES

Using the full wave approach, the single and double scattered electrom agnetic fields from deterministic one-dimensional rough surfaces are c omputed. Full wave expressions for the single and double scattered far fields are given in terms of multidimensional integrals. These integr als are evaluated using the Cornell National Supercomputer IBM/3090. A pplying the steepest descent approximation to the double scattered fie ld expressions, the dimensions of the integrals are reduced from four to two in the case of one-dimensional rough surfaces. It is shown that double scatter in the backward direction is significant for near norm al incidence when the rough surface is highly conducting and its mean square slope is very large. Even for one-dimensional rough surfaces, d epolarization occurs when the reference plane of incidence is not para llel to the local planes of incidence and scatter. A geometrical optic s approximation is used to interpret the results of the double scatter ed fields for normal incidence near backscatter. The physical interpre tation of the results could shed light on the observed fluctuations in the enhanced backscatter phenomenon as the angle of incidence increas es from near normal to grazing angles. The results show that double sc atter strongly depends upon the mean square slope, the conductivity of the rough surface and the angle of incidence. (C) 1994 Academic Press , Inc.