Bistatic scattering from a 3D target above randomly rough surface

This paper presents a hybrid iterative algorithm of analytic Kirchhoff Approximation (KA) and numerical method of moment (MoM) for scattering computation from a three-dimensional (3D) perfect conducting target above a randomly rough surface. The coupling integral equations (IEs) are derived based on the Green´s function and the boundary conditions. The MoM with the Conjugate Gradient (CG) approach is used to solve the target´s IE, and the KA is applied to scattering from the rough surface. The coupling iteration takes account the interactions between the target and the underlying rough surface. Convergence of the hybrid KA-MoM algorithm is numerically validated. Since is only one numerical integral of induced current on the target performed by KA computation, much memory and computation time is reduced. Bistatic scattering from a PEC cubic or spheroid target above a Gaussian rough surface are numerically simulated.