Classification of Underwater UXO from Dynamic EMI Survey Data
Shawn Mulvaney | U.S. Naval Research Laboratory
Leveraging the lessons learned in ESTCP MR-201610 and with the extensive fielding of the Black Tusk Geophysics (BTG)/Gap Explosive Ordnance Detection (GapEOD) UltraTEM Marine family of systems in Europe, the objective of this project is to integrate a high power, advanced geophysical classification-grade electromagnetic induction (EMI) sensor array in the marine towed array (MTA) platform to provide dynamic UXO classification at standoff distances compatible with the MTA’s maneuvering profile through the water. The performance of the integrated system will be demonstrated at a blind-seed validation site like the Underwater Test Site being established at Sequim Bay, WA.
The MTA is a unique, underwater sensor platform that was developed and successfully demonstrated at multiple marine venues in support of past SERDP and ESTCP projects beginning in 2004. The MTA platform operates as an underwater, flying wing style towed sensor array. The UltraTEM system, a multicomponent, multi-sensor system that uses time-domain EMI to detect and characterize buried metal, can be deployed for both terrestrial and marine applications. The UltraTEM system has proven its unique capabilities in European-based production surveys for large area Munitions and Explosives of Concern (MEC) detection, deep large MEC detection, detection of ground-engaging tools in mine stockpiles, and the clearance of harbors before dredging. BTField is a Windows .NET software package built on BTG’s well-known DAGCAP-validated UXOLab software suite. Developing UXOLab in the MATLAB environment has meant that advancements made through SERDP-funded projects are readily incorporated into UXOLab where they can be rigorously tested. Key algorithms and capabilities from UXOLab have been ported to the BTField software, which is well suited to large scale production projects run by industry geophysicists.
Remediation of the anticipated inventory of underwater Department of Defense (DoD) sites with MEC contamination using current available technologies is estimated to cost billions of dollars. As with terrestrial MEC detection and classification, an advanced marine EMI sensor system with strong dynamic classification ability has the potential to significantly reduce remediation costs through reduction in the number of items that need to be dredged and screened from sediment or recovered by divers. The UltraTEM/MTA Marine system is designed to provide a cost-effective means by which these sites can be mapped in a single pass (eliminating the need for multiple surveys), while providing specific information about the extent and nature of MEC contamination. The UltraTEM/MTA system has the potential for significant clean-up cost savings, as well as enabling DoD to apply No Further Action status at previously suspect sites. The DoD would greatly benefit from the application of such a technology at their underwater MEC sites by achieving significant cost savings while simultaneously improving both worker and public safety.
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