Detecting Buried Mines in Ground Penetrating Radar Using a Hough Transform Approach Mark J. Carlotto (mark.carlotto@veridian.com) Veridian Systems Division P.O. Box 134008, 1975 Green Road, Ann Arbor, MI 48113-4008 Abstract A method for detecting buried mines in ground penetrating radar (GPR) data using a Hough transform approach is described. GPR is one of three sensors used in the Mine Hunter/Killer (MH/K) system for detecting buried mines. A buried mine modeled as a point scatterer in object space gives rise to a hyperbolic response in GPR measurement space. Our approach uses the Hough transform to recover the object space representation (i.e., the location of mines in x, y, and depth) from the GPR data, in effect 'deconvolving' the response of the radar. This is done by having each point in measurement space vote for all points in object space where the mine could be located. Against a baseline energy detector, the Hough algorithm shows a one half order reduction in false alarm rate at a fixed probability of detection for low metal, metal, and non metal mines. Introduction Ground penetrating radar (GPR) is one of three sensors used in the Mine Hunter/Killer (MH/K) mine detection and neutralization system. The GPR used on the MH/K is a stepped frequency radar. Individually, each of the 20 antennas are excited with a sinusoidal tone. The tone is transmitted for a specified dwell time, then a sample of the earth response is taken. The sinusoidal tone is then stepped to the next frequency until 128 frequencies from 500 MHz to 2000 MHz have been transmitted and sampled. After the frequency scan the next antenna is scanned until all 20 have collected the 128 samples. After the vehicle moves 2”, the process repeats. The 128 frequency samples are processed into depth. This involves several steps including: calibration, ground surface rejection, and finally a 1D FFT in depth. Figure 1 shows the signature produced from a typical landmine. It is a 2D representation of the 3D data in which each panel shows 34” of along-track vs. depth return data. The panels correspond to adjacent antennas. The antennas are separated by 6”. For this example a hyperbolic signature may be seen in 4 of the 20 antennas. This roughly corresponds to a beamwidth of 85° in free space.