Automatic 3D mapping of features using GPR

Although GPR is normally capable of detecting the responsefrom buried plant, accurate detection and mapping of extended geometrical features in 3-dimensional data is often a major problem faced by the radar operators and geophysicists. This paper presents a pattern recognition approach based on the 3-dimensional Hough Transform for the detection of extended linear targets. By transforming spatially extended patterns into spatially compact features in parameter space, a difficult global detection problem in data space becomes a more easily solved local peak detectionproblem in parameter space. This technique allows the combination of qualitative site information and ground truth in order to increase the accuracy of the final result. Improved freedom of movement and accuracy is achieved by logging the movement of the GPR unit using DGPS. The user is presented with a 3-dimensional site survey report detailing the length, depth and orientations (azimuth and zenith) of any pipes, cables or the like.