Triangular ray tubes in electromagnetic scattering calculation using shooting and bouncing ray (SBR)

This paper presents a method that uses triangular ray tubes in place of the conventional rectangular tubes in shooting and bouncing ray (SBR) to calculate radar cross section (RCS). The tubes are the projections of the objects' triangular facets on the plane perpendicular with the incident direction. The computational time of intersection decision between ray tubes and facets is saved, since every tube can shoot on the target and the null tubes that cannot shoot at any part of the target are avoided. This method obtains more accurate computational results than the conventional SBR at the first order reflection, because the incident tubes just cover the target's profile along the incident direction. The numerical experiments of dihedral corner reflector's scattering are performed to validate the accuracy and efficiency of the algorithm. The benchmark of the calculation is the analysis results based on geometric optics (GO) and physical optics (PO) at the first and second reflections, respectively. It is shown that the method presented in this paper has the comparative accuracy in computation of multiple reflection with the conventional SBR, but can save computational time much more. (C) 2015 Elsevier GmbH. All rights reserved.