Estimation of radar cross section in multiple reflection ducts by combination of modified-physical optics and Iterative Physical Optics

Recently, it is necessary to compute electromagnetic scattering at the high-frequencies In this paper, we analyze electrical fields reflected from concave surface scatterer by using the hybrid method. One of the hybrid method for a convex surface is Modified-Vector Physical Optics (MPO) which enhances the accuracy of Physical Optics (IPO) as high-frequency approximation. The other for a concave surface having multiple-reflections, is Iterative Physical Optics which consists in an iterative resolution of wave source to compute the currents on the inner walls of the cavity. We use each of them independently and describe the external scattering by equivalence theorem. We compute the scattered fields by using the hybrid method. We estimate the accuracy of them by use of radar cross section (RCS).