Aspects of efficient shadowing calculation for physical optics analysis of meshed objects

This paper gives an overview of an efficient shadowing judgment algorithm for use in physical optics (PO) based electromagnetic scattering analysis. The geometry of the scatterer is represented by a mesh of triangle elements (N) and the currents by RWG basis functions. A direct approach to shadowing judgment will yield O(N^2) time scaling, which will be very time consuming. The proposed algorithm makes use of a buffer which splits up the field of view of the illuminating source and yields O(N) time scaling. Careful attention has been paid to the optimization of various algorithmic aspects. Numerical results are presented to demonstrate the efficiency and accuracy of the proposed algorithm.