Hybrid PO-SBR-PTD method for composite scattering of a vehicle target on the ground

In this paper, a hybrid method of physical optics (PO) shooting and bouncing ray (SBR) physical theory of diffraction (PTD), is adopted to investigate the composite scattering of a vehicle target on the ground. Where the scattering of ground is calculated by the PO method, the scattering of the vehicle target is computed by the SBR-PTD method, and the mutual couplings between them are solved by the ray tracing technique. In addition, an octree data structure is used to accelerate the ray tracing progress. A forward-backward ray tracing technique is employed to ensure the accuracy of the illuminated facet identification. In numerical simulation, the monostatic and bistatic scattering of a reduced-scale vehicle target are calculated by the SBR-PTD method and compared with the simulation results with the multilevel fast multipole method (MLFMM) in commercial software FEKO. And the composite scattering from a reduced-scale vehicle target on the planar ground by our PO-SBR-PTD method is also compared with the MLFMM. The results show that our methods can greatly reduce the computational time and memory requirement while keeping a satisfactory accuracy. Finally, the composite scattering from the vehicle target on the rough ground is demonstrated and analyzed for different incident parameters. (C) 2020 Optical Society of America