Analysis of Electromagnetic Scattering From Combined Conducting and Dielectric Objects Above Rough Surface Using Hybrid SIE-KA-FMM Method

An efficient hybrid SIE-KA-FMM method is presented to analyze the electromagnetic scattering from combined conducting and dielectric objects above the rough surface. In this approach, the induced electric current on the rough surface is obtained by the Kirchhoff approximation (KA). The single integral equation (SIE) method is utilized to efficiently compute scattering from the composite target with markedly reducing the numbers of unknowns compared with the conventional coupled integral equation method. The fast multi-pole method (FMM) is incorporated for faster operation and less memory requirement. Several examples verify the validation of the hybrid SIE-KA-FMM method. The composite scattering characteristics of diversiform targets above the rough surface are obtained. Moreover, the numerical results with the different permittivity of dielectric part, polarization mode, working frequency, root mean square (RMS) and correlation length of rough surface, incident pitching/azimuth angle, and target height and target category have been analyzed to provide some useful conclusions.