Fast Analysis of Three-Dimensional Scattering from a buried object under a Dielectric Rough Surface using the Characteristic Basis Function Method

The Characteristic Basis Function Method (CBFM) is adapted to analyze the problem of electromagnetic scattering from a 3-D object buried under a 2-D dielectric rough surface. A current-based physical optics (PO) method, called Modified Equivalent Current Approximation (MECA), is used for efficient derivation of the Characteristic Basis Functions (CBFs) for the dielectric body. The interaction between the rough surface and the object is rigorously taken into account to derive accurate solutions for the electric and magnetic current densities on the rough surface. In addition, the adaptive cross approximation (ACA) is implemented to expedite the generation of the reduced matrix. Finally, scattered fields in the far zone are calculated by using the method of azimuthal angular averaging. The proposed approach is demonstrated to be accurate and efficient. Moreover, it is well-suited for applications when the solution for multiple excitations is required.