Advanced electromagnetic induction (EMI) sensors optimized for unexploded ordnance (UXO) classification produced nearly perfect results at the former Camp Butner in North Carolina, rising to the challenge of classifying smaller munitions. In this latest ESTCP Classification Pilot Program demonstration, these new sensors were paired with advanced processing methods to successfully classify munitions from other nonhazardous items on a site with 37-mm projectiles as well as larger munitions items. Successful classification paves the way for reduced costs and an accelerated timeline to remediate munitions-contaminated sites throughout the nation.

Pilot Program Overview

The ESTCP Classification Pilot Program is providing transparent and documented demonstrations of the capabilities of classification technologies in real-world conditions. At present, most munitions response projects use sensors that were originally developed for other purposes and adapted to the munitions response mission. Until recently, it has been common practice to dig every target on the detection list, with the result that often as few as one percent of the items excavated are actually hazardous. Innovative munitions response technologies offer a rigorous, effective, and transparent method for classifying and distinguishing between harmless subsurface scrap and dangerous buried UXO. These technologies are transitioning to the field through demonstrations on live munitions response sites.

Approach 

The pilot program entails a series of demonstrations at live sites of increasing difficulty. The demonstrations to date consist of several combinations of data-collection platforms and analysis approaches, ranging from careful application of commonly used EM61 survey instruments to advanced EMI systems specially designed to maximize classification of munitions. After the survey systems complete data acquisition, all locations for which the sensor detected signals that could potentially correspond to munitions items are marked for investigation.

Multiple groups of demonstrators employ a variety of classification approaches. Mature, physics-based analysis methods are used to estimate properties of buried objects such as size, depth, aspect ratio, and electromagnetic decay rates—properties that may be useful in distinguishing munitions from other sources. Advanced classification algorithms use this information to determine whether a signal is likely to arise from a munitions item or another source.

Sites are seeded with inert munitions and all anomalies are dug to confirm technology performance. Demonstrators are scored based on their ability to eliminate nonhazardous items while retaining all detected munitions. The results from the former Camp Butner are highlighted here.

Former Camp Butner Results

The demonstration at the former Camp Butner showed outstanding classification potential using advanced EMI sensors on a site that contained the challenges of higher anomaly density and the presence of 37-mm projectiles with larger munitions. Because of these complications, carefully collected survey data from commercial EMI sensors were of much less value than in previous demonstrations. The best analysts using the EM61 survey instrument were only able to correctly classify about 10 percent of the non-hazardous clutter at the point where they identified all the munitions. In contrast, the advanced sensors were able to correctly identify all UXO while correctly classifying more than 1,900 of the 2,100 clutter items. A simple cost model based on these results shows the potential for large savings as the classification approach is adopted on munitions response sites.

Ongoing and Future Demonstrations

ESTCP plans to continue demonstrating the classification process at increasingly complex sites. Upcoming 2011 demonstration sites and their challenging conditions include:

• Former Mare Island Naval Shipyard, California – an ammunition production and storage/handling area with unique characteristics compared to former munitions ranges
• Former Camp Beale, California – a partially wooded site posing challenges for sensor navigation and containing a wide mixture of munitions
• Pole Mountain Target and Maneuver Area, Wyoming – a site with munitions ranging from the smaller 37-mm projectiles to much larger projectiles

Demonstrations at additional sites in the future will focus on heavy vegetation and obscured sky view as well as the development of implementation strategies in conjunction with site stakeholders.

For further information on the ESTCP Classification Pilot Program, visit Featured Initiatives > Munitions Response Initiatives > Classification Applied to Munitions Response.