Scattering by Perfectly Conducting Cylindrical Targets Hidden below a Multilayered Medium

Abstract

An approach to solve the scattered field by perfectly conducting cylinders with circular cross-section, placed below a multilayered medium, under illumination by a line source, is presented. In principle, the interaction of the field scattered by the targets with the multilayer above leads to an infinite number of scattered fields, excited as multiple reflections in each layer by the interfaces. Nevertheless, the developed theoretical formulation is a very compact one, as only two scattered-field contributions are used in each layer, a down-propagating term, described as scattered-reflected field, and an up-propagating one relevant to the scattered-transmitted field. Suitable basis functions, i.e., cylindrical waves expressed through plane-wave spectra, are employed, which are defined through reflection and transmission coefficients of a multilayered medium. As shown in the numerical implementation, the method can be applied to the modeling of several radar problems of targets in complex environments. For example, the technique can be employed to model buried cylinders in geophysical scenarios, in Ground Penetrating Radar applications. The modeling of scattered field by hidden targets in Through-the-Wall radar surveys is another possible field of use. The multilayer may, indeed, model a stratified masonry, but also a room hiding a target in a buildings' interior.