Validation of 2D inverse scattering algorithms from multi-frequency experimental data

Reconstructions of two dimensional dielectric or conducting objects from mu lti-frequency experimental data are considered in the present paper. Two di fferent iterative methods are used for solving the inverse scattering probl em. The first one is based on a boundary integral formalism and retrieves b oundaries and complex permittivities of unknown homogeneous scatterers. For this method initial guesses are derived from method of decomposition of th e time reversal operator (DORT) combined with a low frequency approximation . The second method is based on a domain integral formalism and retrieves t he relative complex permittivity distribution inside some investigated doma in. The data were carried out in a controlled environment (anechoic chamber ) and the reconstructions have been performed using multifrequency approach , i.e., the scheme starts with the lowest available frequency and uses the final result as initial guess at higher frequency in order to enhance the r esolution.