A hybrid method for analyzing scattering from conducting bodies straddling the interface of a half space

A hybrid method of the half-space multilevel fast multipole algorithm (HS-MLFMA) and the adaptive cross approximation (ACA) algorithm is presented to determine the electromagnetic (EM) field scattered from perfectly electronically conducting (PEC) bodies straddling the interface of a half space. When both the source and observation points are located in the same side of the interface, where the observation points are also not close to the interface, the effect of the interface can be approximated with a single image. Therefore, the interactions can be calculated by using the MLFMA. For other situations, the complicated couplings are evaluated with the kernel-independent ACA algorithm. Several numerical examples are demonstrated to validate the proposed scheme.