Full-polarimetric GPR system for underground targets measurement

A conventional GPR system includes PC, network analyzer, rectangular coordinates robot and a single antenna for transmission and reception, resulting in a response only to Co-Polarization signal. However, we expect that more polarimetric information can be obtained. So we developed a full-polarimetric GPR system including PC, network analyzer, position controller, switch driver and polarimetric antenna array. This antenna array can obtain CMP multi-offset data gather directly. At every measurement position, the total of three signals was collected not only in Co-Polarimetric mode but also in Cross-Polarimetric mode. Two groups of experiments have been presented. The first group is concerned with a metal dihedral which is made of two orthogonal conducting plates and a metal trihedral as the targets. The result of this experiment shows that the surface morphology of the target characteristics, the relative position and attitude have a certain influence on the measurement results. The second group is using a metal trihedral as the target. The results of experiment are shown in this presentation are consistent with the theoretical values and helps us to identify target attributes such as direction.