Detection of landmines by vapor-phase sensing of key chemical signature compounds was first demonstrated in 1998 using a sensor we developed as part of the DARPA Dog's Nose Program. This sensor utilizes novel fluorescent polymers to detect ultra-trace concentrations of nitroaromatic compounds emanating from explosives contained in landmines. Much has been learned about the chemical signature of landmines in recent years. For example, it has been shown that the landmine chemical signature tends to be heterogeneous and can be dispersed in the environment near the mine location. This makes it difficult to pinpoint the exact location of the mine using trace chemical detection methods. However, evidence currently available indicates that it may be possible to isolate a mine location to within a small, well-defined area. Data supporting this conclusion have been obtained using our sensor, and the conclusions drawn have been supported using other accepted laboratory analysis methods. Often, minefields contain relatively few mines. Methods of sampling suitable for rapidly isolating the mined areas from large, mine-free areas are being pursued. High-volume vapor sampling and soil particle sampling strategies are being refined for this application. Preliminary data from field tests using prototype samplers and sensors will be presented.
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