Simultaneous multi-frequency TE/TM polarization inversion based on FDFD for ground penetrating radar

In Ground Penetrating Radar (GPR), inversion techniques like Contrast Source Inversion (CSI) have been applied extensively. In this paper, CSI is applied to handle 2D TE/TM-polarized excitations, in which the form for the TE-polarized Maxwell operator is equivalent to the 3D Maxwell operator. Furthermore, a simultaneous TE/TM polarization CSI method based on Finite Difference Frequency Domain (FDFD) together with a frequency hopping scheme is proposed, in which FDFD is able to handle heterogeneous background media. 2D simulation results verify the advantage of the proposed inversion scheme. Since the proposed method is based on a 2D Maxwell operator which has a similar form as the 3D Maxell operator, it can be extended to a 3D CSI-scheme straightforwardly.