Landmine signatures in ground penetrating radar

The Mine Hunter/Killer system employs a ground penetrating radar (GPR) sensor. Twenty antennas sample a 3m swath to measure a 3D depth return from the earth as the vehicle moves forward in a lane. Data has been collected on shallow and deep, metal and low metal landmines. Sample signatures from a metal and plastic cased landmine buried at 6" are presented. In each example a hyperbolic signature is observed. Two feature sets that exploit the hyperbolic shape for false alarm reduction are presented. The first uses a pixel clustering technique to isolate the hyperbola in three dimensions. A vector of size/shape features is extracted and combined with a quadratic polynomial discriminant (QPD) into a single value. The second feature set utilizes the radon transform. The radon transform sums the tails of the hyperbola allowing the algorithm to differentiate between surface clutter, which tends to be oriented horizontally in depth, and the diagonals of the hyperbola. Performance curves for both the 3D size/shape features and the radon feature are presented.