Contents I. Introduction
In many disciplines throughout science and engineering, microwave imaging has become more attractive due to its high sensitivity to the dielectric properties of the targets, which is very useful for detecting of unknown objects in a noninvasive fashion. These applications include applied geophysics, biomedical and industrial diagnostics, or subsurface sensing. In the published literatures, one may find a class of techniques, which aims at quantitatively imaging the medium parameters, and other class of techniques in which the qualitative imaging of the reflectivity is the main goal. In the following, we refer to these techniques as “inversion” and “migration,” respectively.
