# Modeling and Predicting Surface Roughness via Transformation Optics

2014-08-28
Monte Carlo analysis of surface roughness in electromagnetic scattering problems is presented by using the principles of transformation electromagnetics/optics in finite methods. The main motivation in the proposed approach is to eliminate the need of mesh generation for each surface in repeated Monte Carlo realizations, and hence, to devise a faster model in predicting surface roughness. A single, simple and uniform mesh is employed assuming a smooth surface and ignoring the actual surface, and thereafter, a transformation medium is designed on the smooth surface to make this problem equivalent to the original problem with actual surface. The material parameters of the transformation medium are determined by transforming the smooth surface to the actual surface through a specially-defined coordinate transformation. The technique is demonstrated via various finite element simulations.

# Suggestions

 A Numerical Model for Investigating the Effect of Rough Surface Parameters on Radar Cross Section Statistics Kuzuoğlu, Mustafa (2017-07-14) Electromagnetic scattering from rough surfaces is modeled by combining the periodic finite element method and the transformation electromagnetics approach. The behavior of the radar cross section (RCS) at both specular and backscattering directions is analyzed as a function of rms height and correlation length with the help of Monte Carlo simulations. The concept of backscattering enhancement is illustrated, and some conclusions are drawn about the RCS statistics.
 Investigation of rough surface scattering of electromagnetic waves using finite element method Aşırım, Özüm Emre; Kuzuoğlu, Mustafa; Özgün, Özlem; Department of Electrical and Electronics Engineering (2013) This thesis analyzes the problem of electromagnetic wave scattering from rough surfaces using finite element method. Concepts like mesh generation and random rough surface generation will be discussed firstly. Then the fundamental concepts of the finite element method which are the functional form of a given partial differential equation, implementation of the element coefficient matrices, and the assemblage of elements will be discussed in detail. The rough surface and the overall mesh geometry will be imp...
 Implementation of coordinate transformations in periodic finite-element method for modeling rough surface scattering problems ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (2016-05-01) The coordinate transformation technique (with its current name of transformation electromagnetics) is applied to the finite-element method (FEM) with periodic boundary conditions for efficient Monte Carlo simulation of one-dimensional random rough surface scattering problems. In a unit cell of periodic structure, two coordinate transformations are used, one of which is a real transformation designed to model the rough surface with flat surface, and the other is a complex transformation used to design a perf...
 Improving the accuracy of the surface integral equations for low-contrast dielectric scatterers Ergül, Özgür Salih (2007-06-15) Solutions of scattering problems involving low-contrast dielectric objects are considered by employing surface integral equations. A stabilization procedure based on extracting the non-radiating part of the induced currents is applied so that the remaining radiating currents can be modelled appropriately and the scattered fields from the low-contrast objects can be calculated with improved accuracy. Stabilization is applied to both tangential (T) and normal (N) formulations in order to use the benefits of d...
 Finite Element Domain Decomposition Method for Rough Sea Surface Scattering ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (2019-12-31) Full-wave solution of electromagnetic wave scattering from rough sea surfaces is achieved by the Finite Element Domain Decomposition (FEDD) method. The method is implemented in a non-iterative manner by dividing the computational domain into overlapping subdomains, and solving the problem in each subdomain by attaching Locally-Conformal Perfectly Matched Layer (LC-PML) at the truncation boundaries. Statistical behavior of the Radar Cross Section (RCS) is investigated by Monte Carlo simulations. The results ...
Citation Formats
O. Ozgun and M. Kuzuoğlu, “Modeling and Predicting Surface Roughness via Transformation Optics,” 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53699. 