A hybrid method to calculate the composite electromagnetic scattering from a target above a rough surface

The purpose of this study is to describe a new hybrid method based on the reciprocity theorem, the physical optics (PO) and the Kirchhoff approximation (KA) for calculating the composite electromagnetic scattering from a target above a one-dimensional rough interface. The KA method is used to investigate characteristics of electromagnetic scattering from the rough interface (including the equivalent electric current densities and the scattered field from the rough interface). The scattered field from the isolated target was simulated by the PO method. Based on the reciprocity theorem, the multiple scattering up to 3^rd order by the target and the underlying randomly rough interface was considered. The validity of our methods is shown by comparing our results with that of Method of Moments (MoM). It is found that our methods are in good agreement with MoM and has a higher computational efficiency.