Multi-Frequency/Multi-Scaling Techniques for the Electromagnetic Inversion of Lossless Profiles: A Numerical Comparison

Starting from the iterative multi-scaling approach developed for monochromatic illuminations, two multi-resolution strategies have been studied for dealing with multi-frequency inverse scattering experiments. The first approach is based on a multi-scaling frequency-hopping reconstruction scheme, while the second one is concerned with a simultaneous multi-resolution processing of multi-frequency data. In this contribution, a comparative assessment is performed by means of a set of representative experiments in order to evaluate the reconstruction accuracies of the proposed implementations also in comparison with the monochromatic multi-step process.