A Refined GTD Ray System for an Embedded Object and its Polarimetric Behavior

Abstract

A refined ray system based on the Geometrical Theory of Diffraction (GTD) for an object embedded in soil for a monostatic transmitter-receiver alignment is presented here. Apart from the investigation of the ``classical" reflections from the target, creeping waves are also taken into account and their formalism is presented. The objective of such a ray set is to better understand the different scattering mechanisms, which are presented in the complex scattering framework. In electromagnetic modelling based on GTD, a complex shape of a target is replaced by simpler canonical objects e.g. facets, cones, wedges, spheres or cylinders. Here, a cylinder is located in parallel and closely to the plane interface of two dielectrics half-spaces. In this paper, an example of air-soil is taken into analysis. The numerical results obtained from a varying incidence field are employed to describe the polarimetric characteristics of the diffracted field from grazing to perpendicular incidence for a transceiver. By representing the diffracted GTD field on the Poincaré sphere, the location on the sphere has a one-to-one relationship to the dielectric properties of the soil.