Copyright © 2012 Fenglong Qu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper is concerned with the problem of scattering of time-harmonic electromagnetic waves by a penetrable, inhomogeneous, Lipschitz obstacle covered with a thin layer of high conductivity. The well posedness of the direct problem is established by the variational method. The inverse problem is also considered in this paper. Under certain assumptions, a uniqueness result is obtained for determining the shape and location of the obstacle and the corresponding surface parameter from the knowledge of the near field data, assuming that the incident fields are electric dipoles located on a large sphere with polarization . Our results extend those in the paper by F. Hettlich (1996) to the case of inhomogeneous Lipschitz obstacles.