Reliable Approach for Composite Scattering Calculation From Ship Over a Sea Surface Based on FBAM and GO-PO Models

A reliable method based on facet-based asymptotical model, geometrical optics and physical optics (GO-PO) is developed to calculate composite scattering from 3-D complex ship targets over a rough sea surface. The backward ray-tracing is described to identify the visibilities of patches to the incident wave and the reflected wave of other patches on the target and facets on the sea surface. Both the scattering from target, including higher orders of scattering and the interactions between the target and rough sea surface, can be treated handily by the proposed GO-PO method. The accuracy of the target scattering and composite scattering is demonstrated by comparing with Multi-level fast multipole method (MLFMM), method of equivalent currents, and four-path model. Moreover, numerical examples of radar cross section estimation, electric current distribution, and synthetic aperture radar imagery simulation from a real ship target over a randomly rough sea surface are presented and discussed.