A Hybrid Dual-Polarization GPR System for Detection of Linear Objects

To circumvent the polarization sensitivity of ground penetrating radar (GPR) in detecting a linear object, we propose a simple hybrid dual-polarization GPR system consisting of a circularly polarized spiral antenna for transmit and two orthogonally oriented Vivaldi antennas for receiving two linear polarizations. The hybrid combination of a spiral antenna with two Vivaldi antennas is demonstrated to operate in an ultrawideband, to have small antenna dispersion, and to possess favorable antenna isolation. The improved performance of the proposed GPR system over a conventional single-polarized one in detecting linear subsurface objects is indicated by a laboratory experiment in a sandpit. Moreover, the proposed system enables fully coherent dual-polarization measurements with a single transmitter.