Landmine signatures in ground-penetrating radar

Abstract

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 signaturesfrom a metal and plastic cased landmine buried at 6 " are presented. In each example a hyperbolic signature is observed. Twofeature sets that exploit the hyperbolic shapeforfalse alarm reduction arepresented. 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 secondfeature set utilizes the radon transform. The radon transform sums the tails ofthe hyperbola allowing the algorithm to dfferentiate between surface clutter, which tends to be oriented horizontally in depth, and the diagonals ofthe hyperbola. Performance curvesfor both the 3D size/shapefeatures and the radon feature are presented.