Position determination of a subsurface object by combined output of two receive GPR antennas

A new algorithm is proposed for subsurface object detection and 3D localization using ground-penetrating radar (GPR) data, if GPR antennas are slightly elevated above the ground. Due to an effective approximation, the algorithm solves problems linked to calculating the position of the refracting point of electromagnetic waves on the air-ground interface. We present how the typical hyperbolic object signature can be detected on a B-scan. Then, we argue that only one surface coordinate can be extracted from the hyperbola detected in one B-scan, so that additional information is needed to find the transverse object position. We show that an antenna configuration with two receive antennas solves this problem. The problem of extracting the third object coordinate as well as the propagation velocity of electromagnetic waves in the ground is also addressed. The algorithm is illustrated on a data set acquired by this antenna configuration.