ITERATIVE HYBRID METHOD FOR ELECTROMAGNETIC SCATTERING FROM A 3-D OBJECT ABOVE A 2-D RANDOM DIELECTRIC ROUGH SURFACE

An iterative hybrid method combining the Kirchhoff approximation (KA) and the multilevel fast multipole algorithm (MLFMA) is studied for electromagnetic scattering from a three-dimensional (3-D) object above a two-dimensional (2-D) random dielectric rough surface. In order to reduce the computational costs, some treatments have been studied. Firstly, the fast far-field approximation (FAFFA) is utilized to speed up the electromagnetic coupling interaction process between the rough surface and the object. Secondly, based on the scattering mechanism of the rough surface, a truncation rule on moderate rough surface for bi-static scattering is proposed under the plane wave illumination, which can further speed up the iteration. Compared with the conventional methods, the hybrid method with the above treatments is very efficient to analyze the scattering of a 3-D object above random rough surfaces. Simulation results validate the effectiveness and accuracy of the iterative hybrid method.