A GPR Able to Detect Its Own Position Using Fixed Corner Reflectors on Surface

Ground penetrating radar (GPR) systems are equipment able to acquire underground images scanning the surface of the soil/pavement under investigation. Usually GPR records its own position along the scan line using a mechanical odometer, i.e., a rolling wheel in contact with the ground. Unfortunately, this simple and cheap solution can be not effective on uneven terrains. In this article, a completely different solution is proposed for retrieving the radar position along the scan. An additional couple of transmitting/receiving (TX/RX) antennas detects the distance of one or two corner reflectors (CRs). As the signal backscattered by the CR appears in GPR trace (with a suitable delay for separating air and ground signals), the position data are co-registered in the radar trace itself and no external synchronization is necessary. The technique has been successfully tested both for detecting the position of the radar along a line (1-D case) and on a surface (2-D case).