A new adaptive multiscale scheme for solving multi-frequency microwave laboratory-controlled data

The goal of microwave inverse scattering is to reconstruct the permittivity distribution of a target from measured scattered field data. In order to solve this nonlinear and ill-posed problem, several methods have already been developed. A newly designed adaptive multiscale approach, based on spline pyramids is proposed. This new scheme, which leads to strongly reducing the computational time of the refinement step in comparison with our previous approach (Baussard, A. et al., Inverse Problems, vol.20, no.6, p.S1-S15, 2004) and of the global procedure by using a modified gradient method with a positivity constraint, was tested against multi-frequency laboratory-controlled experimental data. The obtained results show the effectiveness of the multiscale adaptive approaches.