A Hybrid Analytic-Numerical Algorithm of Scattering From an Object Above a Rough Surface

A hybrid algorithm, combining analytic Kirchhoff approximation (KA) and numerical method of moments (MoMs), is developed to solve the coupling electric-field integral equations (EFIEs) of scattering from a perfect electric conducting (PEC) object above a randomly rough PEC surface under TE-polarized plane-wave incidence. The MoM with the conjugate gradient approach is used to first solve the EFIE of the object. The surface fields on the rough surface are analytically expressed using the KA method, and large memory and computations for those fields are greatly reduced. An iterative approach of the surface fields induced on both object and rough surface is then utilized to take into account interactions between the object and underlying rough surface. Convergence of this hybrid algorithm is numerically validated. Making use of Monte Carlo realization, bistatic scattering from a 2-D PEC cylindrical object above a PEC rough surface is well simulated by this hybrid KA-MoM algorithm