SPOT-GPR Analysis of Ground Penetrating Radar Signals Recorded over the Limestone Region of the IFSTTAR Geophysical Test Site: Preliminary Results

Ground penetrating radar (GPR) can be used to map the location of pipes, conduits, cables, and almost any kind of services buried in the shallow subsurface of modern cities, without destroying any structure; this is a crucial task in the frame of civil-engineering works performed in urban areas. Usually, GPR data recorded in underground utility surveys are analysed and interpreted by using manual approaches, which can be a laborious, repetitive, and time-consuming task; there is a strong interest in the GPR scientific community for innovative procedures allowing semi-automated or automated detection and localization of targets from raw or processed GPR data. The free software `SPOT-GPR' was recently developed by Members of COST Action TU1208; this tool can semi-automatically find and localize targets in radargrams. SPOT-GPR applies the matched-filter technique to the radargram under test, partitions it in sub-profiles, and, for each sub-profile, estimates the main direction of arrival of the electromagnetic field scattered by the targets. Next, the software triangulates all the estimated angles and obtains a pattern of intersections condensed around target locations; a statistical method is employed to remove the noisy background of unwanted crossings. Finally, the number of targets and their positions are estimated from the remaining crossings. In this paper, SPOT-GPR is tested with real data taken from the Open Database of Radargrams of COST Action TU1208. Since all data included in such database are available for the scientific community, this case study enables a comparison of SPOT-GPR's method with other algorithms that are being or will be tested on the same data by other authors.