BISTATIC EM SCATTERING ANALYSIS OF AN OBJECT ABOVE A ROUGH SURFACE USING A HYBRID ALGORITHM ACCELERATED WITH THE ADAPTIVE CROSS APPROXIMATION METHOD

Calculating the RCS (Radar Cross Section) of two 3D scatterers needs to numerically solve a set of integral equations involving numerous unknowns. Such a 3D problem cannot be solved easily with a conventional Method of Moments (MoM) by using a direct LU inversion. Thus, hybridization between the Extended Propagation-Inside-Layer Expansion (E-PILE) and the Physical Optics approximation (PO) significantly reduces the memory requirements and CPU time. The resulting method called E-PILE+PO. In this work, we take advantage of the rank-deficient nature of the coupling matrices, corresponding to the interactions between scatterer 1 (the object) and scatterer 2 (the rough surface), to further reduce the complexity of the method by using the Adaptive Cross Approximation (ACA).