Setting the stop dig point for unexploded ordnance remediation

We develop objective methods for determining whether advanced classification with geophysical data has identified all hazardous unexploded ordnance (UXO) at a site. We first propose a simple criterion for selection of the stop dig point: we can stop digging once a specified number (N_stop) of non-UXO are encountered in sequence during ordered excavation of targets. We then develop an objective method for determining N_stop that accounts for the difficulty of a given classification problem. Finally, we show how a binormal model can be fit to the receiver operating characteristic in order to estimate the posterior probability that each target is a UXO.