Detection of buried land mines using ground-penetrating radar

Ground Penetrating Radar (GPR) has become widely accepted as a major technique for subsoil investigations over the recent years, mainly in civil engineering. Another field of application, on a global scale, is the pollution of vast areas with land mines, especially in countries of former armed conflicts. According to UN estimates, the number of buried anti-personnel mines exceeds 100 million, with 15,000 people killed every year. The rate of new mines being layed is about one million per year and surpasses the number of mines cleared by a factor of twenty. This demonstrates the need to develop new technologies to increase the efficiency of mine clearing operations. The intension of this paper is to give a short review of the underlying principles and limitations of the GPR-technique. The advantage of 3D versus 2D image processing techniques to enhance data quality and thus detection probability is demostrated, using measured data from sandbox experiments with buried plastic mines. The processed data presented show vertical and horizontal planes through the subsurface and give a clear indication of the buried objects. Factors determining the resolution of the method are discussed. Measurements taken from stones are compared with data obtained from buried mines. The mine data exhibit specific resonances, which is probably due to a minor metal content.