Two novel studies of electromagnetic scattering in random media in the context of radar remote sensing

This thesis is a theoretical study that investigates two different problems in electromagnetic scattering in random media: scattering from a dielectric rough surface and scattering through a volume embedding individual scatterers. These two situations are fundamental in the development of algorithms for the retrieval of geophysical parameters in remote sensing. Each of these two problems is addressed in a separate part of the thesis. The objective of the first part is to demonstrate in what way the integral equation model (IEM) developed by A. K. Fung can be improved, so that the two classical methods in electromagnetic scattering from rough surfaces, Kirchhoff's approximation and the small perturbation model, can be analytically unified within a single formalism. Although this has been achieved by other models, such as the small slope approximation by Voronovich, the widespread use of the IEM by the remote sensing community justifies the interest in exploring the potentials of the IEM. Furthermore, a full revision of the IEM sheds light on many important aspects involving rough surface scattering, including perturbation theory, shadowing effects and the presence of a large-scale, deterministic element in the profile of the surface. The purpose of the second part is to contribute to a line of research in classical scattering theory that remains rather ignored. The method of Feynman diagrams in the many-body problem has had an enormous success in solid-state physics but it can be applied to any linear system in any discipline. Comparisons of results obtained by using this method and other classical approaches are made and a good agreement is found for the simple case of a half-space containing dielectric spheres. (author)Available from British Library Document Supply Centre-DSC:DXN047354 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo