Three-dimensional Buried Mine Positions from Arbitrary RADAR Surface Scans

A method is presented for the rapid evaluation of object posítions in threed imensionsfr om setso f Ground Penetrating Radar (GPR) range measurementsT.h es cansn eedn otf orm a regular raster: ít is necessary only that the scans follow one or more continuows paths. The method extends by the ideas reported by Windsor and Capineri (1998) where the 'ringing' signal from the reflected object signal in any one scan is correlated with that of its neighbours to follow,the ringing signal and so produce a set ofrang,e values covering all the sutface positions where adequately well correlated signals were observed. Randomly chosen sets of three rattge values are then used to solve analytically for the three co-ordinates of the mine position consistent with these ranges. A rapid estimale of the mine position and its statistícal uncertainty is buílt up from numerous selections from the complete surface raster scan. A three-dimensional plot of the results is developed to give an intuitive image of the estimated buried object position and the relative uncertaínty. The method is demonstratedu sing measurementsr ecorded and made available by the DeTeC group at EPFL, Lausanne, Switzerland. A typícal anti-personnel land mine buried at 100 mm nominal depth in sand was evaluated to be at 105 !23 mm. The x and y co-ordinates were positioned to within betler than 32 mm in less thanfive seconds computation time on a PC.