Final Report - Strategic Environmental Research and Development ...

Conclusions and Implications for Future Research/ImplementationWe have assembled a substantial library of EMI signatures of munitions and clutter which hasproven to be quite useful for research purposes and to support development of classificationprocedures. As new, site-specific inert munitions and clutter items become available through theESTCP live site demonstrations they should be measured and included in the library.The results shown in Figure 25 indicate that a decay time interval of about 0.1 ms to 3 ms isadequate for classification. All of the data in our library were collected with decays to 25 ms.Some signals are distorted by run-on effects with shorter transmit pulses, so a degree of cautionshould be exercised when using the library with shorter-decay data.Typical library matching procedures used today only ask how much a given target looks (in theEMI sense) like a target of interest. Since we now have an extensive library of polarizabilitiesnot only for a variety of representative munitions items but also thousands of clutter itemsrecovered from a number of different munitions response sites. Using this database we can askwhether an unknown target is more munitions-like or more clutter-like, which should improveclassification performance. The library-based classification schemes using this approach shouldbe studied in order to determine whether or not they offer improved performance.33