Target Prioritization in TEM Surveys for Sub-Surface UXO Investigations Using Response Amplitude, Decay Curve Slope, Signal to Noise Ratio, and Spatia

To reduce the number of false-positives in identifying UXOs and related debris for an ongoing Site Investigation, a target prioritization routine was developed based on the likelihood of a metallic source. Numerous parameters were evaluated statistically using over 2000 existing intrusive investigation results. Those showing the best ability to discriminate between metallic and non-metallic sources were incorporated into the scheme, including peak amplitude response, power-law decay slope, signal to noise ratio, and spatial match filter response. Parameters were assigned increasing numeric values based on likelihood of a metallic source, and summed to produce a target rank. Subsequent application to over 6000 new intrusive investigations revealed that the highest ranked 25% of targets were nearly five times more likely to yield a metallic source when investigated than the lowest ranked 25%. These results show that target selection routines in UXO investigations would benefit from using more parameters than just magnitude response, allowing more aggressive target identification and reduced costs by lowering the number of false positives that are investigated. Proposed refinements may further increase predictive capabilities.