Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
EM scattering from irregular layered structures based on solutions of generalized telegraphists' equations
Abstract
Upon imposition of the exact boundary conditions at the rough interfaces, Maxwell's equations are transformed into a rigorous set of coupled first-order integro-differential equations for the forward and backward traveling wave amplitudes--generalized telegraphists' equations. In this work only the radiation far fields are considered in detail. Explicit expansions for the scattering coupling coefficients appeared in the generalized telegraphists' equations are derived. A numerical method to solve the generalized telegraphists' equations for the radiation fields is derived for one dimensional rough surfaces. The numerical simulations are carried out for one dimensional deterministic and random rough surfaces. A Monte-Carlo method is applied to carry out numerical simulations for the random rough surfaces. The numerical solutions for the total diffuse scattered fields derived here are in good agreement with the earlier analytical iterative results (Bahar and Rajan, 1979) that accounts for only single scatter, when the maximum surface slope is less than 30 degrees. The generalized field transforms for two dimensional irregular layered structures are also solved here for a three medium scattering problem. Using a first order iterative procedure, the diffuse scattered fields from irregular multilayered structures are shown to be expressed as the sum of the first order diffuse scattered fields from each individual rough interface. For the two dimensional three medium structures with irregular interfaces, the full wave like and cross polarized diffuse scattered fields are derived. The general bistatic Mueller matrix elements are also derived here. They relate the incident to the scattered Stokes vectors. For two dimensionally rough surfaces the vertically and horizontally polarized waves are depolarized upon scattering. The rough surface characteristics is assumed to be homogeneous and isotropic. The surface height, slope, and autocorrelation function are assumed to be Gaussian. The thickness of the coating material is assumed to be uniform. For the numerical simulations only the backscatter case is considered since this analysis is mainly used for remote sensing.
Subject Area
Electrical engineering|Radiation|Optics|Remote sensing
Recommended Citation
Zhang, Yuzhi, "EM scattering from irregular layered structures based on solutions of generalized telegraphists' equations" (1994). ETD collection for University of Nebraska-Lincoln. AAI9519556.
https://digitalcommons.unl.edu/dissertations/AAI9519556