Reflectivity reconstruction from only amplitude non-redundant near-field data: numerical validation

An approach to image the reflectivity profile of a planar target employing only amplitude non-redundant NF data, assuming a monostatic measurement setup, is here proposed. The phase retrieval problem is here dealt with as a quadratic inverse one, which requires two sets of independent squared amplitude measurements of the scattered field, acquired on two distinct scanning surfaces. Particularly, a planar wide mesh scanning is considered. Such a non conventional plane rectangular scanning has been developed by adopting a non-redundant sampling of the squared amplitude of the field scattered by the target regarded as enclosed in a double bowl. This innovative sampling strategy allows a remarkable reduction (about 93%) of the required NF samples as compared to standard measurements. Furthermore, the available a priori information on the object under test are taken into account by adopting an effective representation of the unknown reflectivity distribution, thus improving the accuracy and reliability of the phaseless procedure. A numerical validation of the proposed approach is reported.