Hybrid GRE-PO method for modeling scattering from electrically large targets

Abstract

The generalized ray expansion (GRE) method was originally developed for analyzing high-frequency scattering from the interior of cavities [1],[2]. We propose to combine it with physical optics (PO) to reduce the effort of the initial ray tracing of incident field for efficiently modeling scattering from electrically large and complex targets of general shape. The target is enclosed with a fictitious box which can be rectangular or spherical in shape (see Figure 1). The surface of the box is sub-divided into sub-apertures. Rays are launched from the phase centre of each sub-aperture to the target. Unlike the GRE used for cavity scattering, the rays are limited to the angle subtended by the target and the phase centre. The subsequent ray tracing from one part of the target to another part of the target follows the usual method in PO. © 2010 IEEE.