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

This paper discusses about the generalized ray expansion (GRE) method was originally developed for analyzing high-frequency scattering from the interior of cavities. 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.