TIME-DOMAIN ITERATIVE PHYSICAL OPTICS METHOD FOR ANALYSIS OF EM SCATTERING FROM THE TARGET HALF BURIED IN ROUGH SURFACE: PEC CASE

In this paper, time-domain physical optics (TDPO) method is extended to its iterative version (TDIPO) to consider the coupling effects between two regions, and the latter is employed to investigate electromagnetic scattering from three dimensional target half-buried by a two dimensional rough surface. By using iterative scheme, more accurate transient response reflected from combinative target with multi-scattering effects would be obtained than that by using TDPO alone. The TDIPO could also be enhanced by time-domain equivalent edge current (TDEEC) to further determine the far-field characteristics of the combinative target with rough surface. An accurate composite geometry model technique which combines 2D perfectly electrically conducting (PEC) rough surface and half-buried 3D PEC target is introduced and employed to assist the meshing work. The validity of the presented method is verified by comparing the scattering results for dihedral targets with those obtained through TDPO and finite difference in time domain (FDTD), as well as multi-level fast multiple algorithm (MLFMA). Then simulations of EM scattering from the target embedded in rough surface for different incidence directions are carried out to test the availability of TDIPO/EEC. Discussions on the effects of incidence direction and the presence of the target on the backscattering in far-zone are also given.