PILE method combined with PO for the scattering by coated cylinders, a rough layer and an object below a rough surface
Résumé
In this article, the field scattered by coated cylinders, a rough layer and an object below a rough surface is computed from the efficient PILE (Propagation-Inside-Layer-Expansion method) method combined with the PO (Physical Optics) approximation to accelerate the calculation of the local interactions on the non-illuminated scatterer which is assumed to be perfectly-conducting. PILE method is based on the MoM (Method of Moments), and the impedance matrix of the two scatterers is then inverted by blocks from a Taylor series expansion of the inverse of the Schur complement. Its main interest is that it is rigorous, with a simple formulation and a straightforward physical interpretation. In addition, one of the advantages of PILE is to be able to hybridize methods (rigorous or asymptotic) valid for a single scatterer. Then, in high-frequencies, the hybridization with PO allows us to significantly reduce the complexity in comparison to a direct LU inversion of the impedance matrix of the two scatterers without loss in accuracy.