Mine Detection in Magnetic Soils

Magnetic soils affect the performance of eddy current metal detectors. We have analyzed properties of soil samples both in time and frequency domain. Most of the samples have frequency dependence of susceptibility linear in LogLin scale, which allows effective soil compensation in advanced frequency-domain detectors. However, some difficult soil samples show deviations from loglinearity, which may indicate uneven volume distribution of superparamagnetic grains or the presence of conducting or ferromagnetic particles. This would also cause deviation from the ideal 1/t soil time response, on which relies soil compensation in advanced time-domain detectors. The void effect allows one to detect plastic mines in magnetic soil. We show that in higly magnetic soils it can be caused by the contrast in susceptibility, but not in conductivity.

LEWIS Adam;  RIPKA Pavel;  KUBIK J.; 

2007-07-04

AMER SCIENTIFIC PUBLISHERS

JRC33346