A Fast Physical Optics (FPO) algorithm for high frequency scattering

A novel algorithm referred as the fast physical optics (FPO) for computing the back-scattered field over a range of aspect angles and frequencies is presented. The computation is performed in the framework of the conventional physical optics approximation appropriate for the high frequency scattering regime. The proposed algorithm is, also, directly applicable to fixed angle bistatic configurations and a variety of single scattering formulations. The method comprises two steps. First, a decomposition of the scatterer into subdomains and computation of the pertinent scattering characteristics of each subdomain. Second, interpolation, phase-correction and aggregation of the scattering patterns of the subdomains into the final pattern of the whole body. A multilevel algorithm is formulated via a recursive application of the domain decomposition and aggregation steps. The computational structure of the multilevel algorithm resembles that of the FFT. The proposed method is especially suited for generation of synthetic data for radar imaging simulation.