Inverse obstacle scattering for homogeneous dielectric cylinders using a boundary finite-element method

A method for reconstructing the shape and the permittivity of a penetrable homogeneous cylinder is described, It is the extension to penetrable cylind ers of a previous work dealing with perfectly conducting cylinders. A low-f requency approximation is used to determine an initial guess. Then, a rigor ous boundary integral method permits us to reconstruct arbitrary shapes and complex permittivities. It is based on an iterative conjugate gradient alg orithm requiring the solving of two direct diffraction problems only. A sim ple and original regularization scheme is presented, which ensures the robu stness of the algorithm. Numerical examples with lossy embedding media and additional random noise for both E / / and H / / polarizations are given.