Highly efficient hybrid method for monostatic scattering by objects on a rough surface

A highly efficient hybrid method is proposed for computing scattering by objects above a rough surface. A special treatment is designed and applied to the conventional hybrid method of the Kirchhoff approach (KA) and the method of moments (MoMs) to speed up the computation of the interaction between the objects and the rough surface. To further improve efficiency, the multilevel fast multipole algorithm (MLFMA) and the fast far-field approximation (FAFFA) are employed in the hybrid KA-MoM method. The accuracy and efficiency of the proposed method are validated by numerical experiments.