Analytic Physical Optics Solution to Bistatic 3D Scattering From Separated Dihedral

Constructing the mapping between the geometric object and its corresponding 3D scattering response is a fundamental but challenging task in the domain of electromagnetic scattering, which is crucial for radar target recognition and the 3D structure interpretation. In recent years, the analytic physical optics, as a typical analytic solution, has been successfully utilized to produce the parsimonious, physically relevant 3D bistatic scattering models for standard dihedral and obtuse dihedral. In this paper, the scattering mechanism of separated dihedral, as a canonical structure that often appears in the actual targets, is investigated and its corresponding bistatic 3D scattering model is derived and established by the combination of geometric optics and physical optics method. First, the single and double-bounce reflection, as well as the occlusion occurred under different incident wave angles for the separated dihedral are analyzed in detail. Consecutively, the bistatic 3D scattering responses for different reflection cases are derived by the physical optical integration. Finally, the closed-form solution to bistatic 3D scattering model of separated dihedral is presented. The experiments with the two state-of-the-art electromagnetic calculation methods, shooting and bouncing rays and method of moments, validate the effectiveness of the proposed model. Especially, the experimental results also manifest that the standard dihedral is the specific case of the proposed model.