Fast Algorithm for Angular Sweeping in FEM Based on Interpolative Decomposition

A fast angular sweeping algorithm based on interpolative decomposition was proposed for the finite element method (FEM) to efficiently compute monostatic radar dispersion section (RCS). In the algorithm, an excitation matrix was constructed from multiple right-hand-sides (RHSs) associated with different incidents. Then, interpolative decomposition (ID) was applied to the excitation matrix to figure out the skeleton incidents. After the solutions corresponding to the skeleton incidents were obtained through FEM, the desired angular responses could be reconstructed from those of skeletons. The results of numerical experiments on isotropic and anisotropic dielectric targets show the efficiency and accuracy of the proposed algorithm.