Full wave PILE method for the electromagnetic scattering from random rough layers

This paper presents the rigorous efficient PILE (Propagation Inside-Layer-Expansion) numerical method to calculate the frequency and time responses of the field scattered by two random rough surfaces separating three homogeneous media. Here, the study is applied to ground penetrating radar (GPR) (nadir angle, Ricker pulse, near or/and far field) for nondestructive pavement survey by taking the roughness of the surfaces into account and by calculating the contribution of each echo coming from the multiple scattering inside the layer. The PILE method starts from the Method of Moments (MoM), and the impedance matrix is inverted by blocks from the Taylor series expansion of the inverse of the Schur complement. Its main advantage is that it is rigorous, with a simple formulation and has a straightforward physical interpretation.