Sensor Evaluation Study For Use With Towed Arrays For Uxo Site Characterization

The Naval Research Laboratory is developing a Multi-sensor Towed Array Detection System<br>(MTADS) with support from the DOD Environmental Security Technology Certification Program (ESTCP).<br>In this effort we seek to extend and refine ordnance detection technology to more efficiently characterize OEW<br>sites, identifying nonferrous and smaller items, distinguishing ordnance from clutter and analyzing clustered<br>targets to identify and locate individual targets within complex target fields. Our evaluation shows that these<br>goals are best met by combining magnetic and electromagnetic sensors. We report on field studies at a prepared<br>test range of commercial sensors in arrays in various configurations and including; Cesium vapor<br>magnetometers in single sensor and gradiometric configurations, fluxgate gradiometers, proton procession<br>magnetometers, and electromagnetic pulsed induction sensors. The advantages and disadvantages of each<br>technology and their applicability based upon survey requirements is discussed. We also discuss recommended<br>data densities including horizontal sensor spacings, survey speeds, sensor heights and make recommendations<br>about the appropriate use of gradiometers and active sensors.