Influence of antenna configurations on 2D GPR data: Information from polarization and amplitude measurement

Abstract

Ground Penetrating Radar (GPR) images highly depend on the relative geometry existing between the transmitting and receiving antennas and the depth reflectors. The resulting variations are mainly due to the directional properties of the antennas and also to the sensitivity of the considered reflector to the polarization of the incident electromagnetic wave. In the present study, GPR data sets have been recorded using several 100 MHz antenna configurations, including Transverse Electric (TE) and Transverse Magnetic (TM) modes. In addition, a polarization analysis has been conducted by surveying twice the studied profile in both modes (TE and TM), using parallel and perpendicular antennas. The obtained images display a high complementarity that provides more details on the studied geological structures when compared to an image derived from a single conventional acquisition configuration. These studies emphasize how multi-configuration antennas surveys have the potential to improve GPR imaging and interpretation. Furthermore, polarimetric surveys have been carried out in order to study the possible link between interface depolarization phenomenon and phase wave inversion and amplitude wave decrease observed for TE Common Mid Point gathers. The latter would induce disturbances of the GPR images when stacking procedures are used for multi-offsets surveys.