A Hybrid Approach for Rapid Computation of Two-Dimensional Monostatic Radar Cross Section Problems With the Multilevel Fast Multipole Algorithm

This communication proposes a hybrid acceleration technique for the efficient computation of large two-dimensional monostatic radar cross section (RCS) problems with the multilevel fast multipole algorithm (MLFMA) for three-dimensional scattering objects. The described approach combines a spectral low-rank preconditioner with an efficient angular response computation based on a low-rank compression of the right-hand side matrix. In this communication the low-rank decomposition is done using the adaptive cross approximation (ACA), since conventional approaches are hardly applicable to large excitation matrices. The proposed technique turns out to be highly efficient and accurate for the solution of large 2D monostatic RCS problems involving 3D geometries.