Potential Impacts of 3-D Polarized GPR Data on Full-Waveform Inversion

Ground Penetrating Radar (GPR) is a powerful tool for exploring the shallow subsurface due to its effective and noninvasive features. Recently, accurate and high-resolution characterization of subsurface properties in three-dimensional (3D) GPR investigations calls for a quantitative and high-resolution imaging approach. However, the full-waveform inversion (FWI) method for GPR data was performed mostly in 2D and rarely discussed the polarizations. To fully utilize 3D GPR polarization data, this letter proposes a frequency-domain FWI algorithm for simultaneous inversion of both the co-polarized and cross-polarized data. Detail derivations and vital processes in our inversion workflow were described in detail, before applying it to the numerical experiments and analyzing the potential impacts of the polarizations on inversion results with a synthetic model. Results showed that the cross-polarized data is more sensitive than the co-polarized data in inversion, and the behaviors in the inversion of the multi-polarized data with different values in the weighting matrix suggests that larger weights for co-polarized data is of benefit to a better inversion result.