Beginning with a review of the current need for identification of buried and surface unexplored ordnance such as mines, shells, bombs, this book then explains existing techniques for electromagnetic detection of such targets. A detailed treatment of target signatures (natural frequencies and related parameters) for identification and discrimination of false alarms is also given.

Unexploded ordnance (UXO) cleanup is the number one priority Army installation remediation restoration requirement. The problem is enormous in scope, with millions of acres and hundreds of sites potentially contaminated. Before the UXO can be recovered and destroyed, it must be located. UXO location requires surface geopbysical surveys. The geophysical anomalies caused by the UXO must be detected, discriminated from geophysical anomalies caused by other sources, and ideally identified or classified. Recent UXO technology demonstrations, live site demonstrations, and practical UXO surveys for site cleanup confirm that most UXO anomalies can be detected (with probabilities of detection of 90 percent or better), however there is little evidence of discrimination capability (i.e., the false alarm rates are high), and there is no identification capability. Approaches to simultaneously increase probability of detection and decrease false alarm rate and ultimately to give identification/classification capability involve rational multisensor data integration for discrimination and advanced development of new and emerging technology for enhanced discrimination and identification. The goal of multisensor data integration is to achieve true joint inversion of data to a best-fitting model using realistic physics-based models that replicate UXO geometries and physical properties of the UXO and surrounding geologic materials. Data management, analysis, and display procedures for multisensor data are investigated. A magnetic modeling capability is developed, validated, and documented that uses a prolate spheroid model of UXO. The electromagnetic modeling of UXO signatures is more problematic, and an intermediate quasi-empirical modeling capability (a simple analytical model modified to reflect measured signature observations) is explored.

This report describes a set of field tests conducted at Badlands Bombing Range (BBR) in South Dakota in September 2002. The primary goal of the field tests was to evaluate parameters critical to the design of an airborne electromagnetic system capable of detecting a variety of buried ordnance. The resulting system, called ORAGS-TEM, was patterned after the low-flying helicopter magnetic systems under development at ORNL through separate SERDP/ESTCP programs. Thus, the ORAGS-TEM has a frame mounted, multiple sensor design that permits helicopter surveys at altitudes as low as one meter over UXO-contaminated terrain. As with the magnetic systems, GPS and laser altimetry provide precise positioning to within a few tens of centimeters.