Optimal Signal-to-Clutter Ratios for the Efficient Detection of Buried IEDs

Abstract

Buried IEDs are a significant threat and have been directly responsible for a large number of American soldier casualties in the Middle East. Significant resources have been committed including the deployment of sensor borne UAVs in an effort to neutralize these and other classes of IED threats.Possible approaches to detecting buried IEDs in the LWIR that have been investigated include the examination of the reststrahlen spectrum and polarization. In general, both the signals and persistence of these signals are relatively weak. However, the signal resulting from differences in the heat transfer properties between the disturbed and undisturbed soil, even in the presence of the IED, is strong and has potential to persist over days, weeks, and even months.Detection of the IED signal that arises from heat transfer is confounded by competing clutter objects. These clutter signals are generated by rags, bricks, wood, paper, metal, and many other items. We recognize however, that the time varying signatures of clutter objects are driven by heat transfer processes that are significantly different from those of disturbed soil. Consequently, there may be times during the diurnal cycle when the clutter signals are low and the disturbed soil signature is sufficient for detection.Using large scale terrain models consisting of hundreds of millions of thermal nodes we have shown that in desert environments these periods of high signal-to-clutter ratios exist for many clutter objects. Consequently, we are building a tool which, given standard weather forecasts, will estimate when these favorable periods to fly LWIR sensors will occur. We will present the results of this research and show our approach to building this IED detection aid.