Characterization of inhomogeneous cylinders from transient data

In this paper we propose a non linear inversion approach, which is able to characterize a scattering system from the knowledge of the transient scattered field measured when only one electromagnetic source is used to illuminate the objects. Such a source radiates a double-frequency Gaussian incident pulse, that is a pulse shape whose spectrum assumes its maximum value around two different frequencies. The inversion problem is formulated in the frequency domain rather than directly in the time domain and an iterative method is exploited to retrieve the unknown permittivity and conductivity profiles. The proposed strategy works in the canonical two-dimensional scalar case and its reconstruction capabilities are tested against experimental data concerning inhomogeneous targets.