Development of a Real-Time Underwater Magnetometer Array by Dr. Mark Prouty

This project supports SERDP’s efforts to significantly improve the ability of the Department of Defense to detect, characterize and remediate military munitions found at underwater sites. Total field magnetometers are commonly used in land and marine environments to detect and analyze unexploded ordnance (UXO). Such sensors make highly precise measurements of the Earth’s magnetic field. Ferrous material, such as the steel of munitions items, alters this magnetic field, and can therefore be detected by making measurements near the object. Multiple measurements are necessary to determine the object’s location. With previous sensors, very few sensors would be used to gather data, which would then be analyzed later. Once the properties of an anomaly are determined, the position of the object is noted, but must then be reacquired by going back to the site. This presentation described the development of technology eliminating this multi-step approach. With the development of significantly smaller and lower power devices, many sensors can be deployed simultaneously, thereby allowing the data analysis necessary to locate targets and determine relevant properties to be performed at once. This will greatly improve the efficiency of remediating UXO, especially in underwater environments.

Underwater Electromagnetic Sensors: UXO Detection and Classification in Marine Environments by Dr. Thomas Bell

Electromagnetic induction (EMI) sensor technology has proven very effective for detecting and identifying buried unexploded ordnance at munitions response sites on land. In particular, signals from the elements of a suitably designed sensor array positioned over an object can be combined to determine whether or not the object is of a size and shape consistent with intact munitions items. A large number of underwater sites potentially containing munitions have been identified by the U.S. Army Corps of Engineers (USACE) and the U.S. Navy. The marine environment introduces complexities in the response of electromagnetic sensors that can adversely affect their performance. In this webinar presentation, we drawn on the results of recent SERDP projects in exploring the physical and operational difficulties which are encountered in adapting EMI classification technology to underwater applications. These include attenuation and distortion of EMI signals by seawater, competing signals from surrounding sediments as well as the seawater itself, the effects of corrosion and biofouling on the EMI response of munitions items, and the difficulties in getting sensors close enough to the bottom to elicit adequate responses from targets of interest.

Dr. Mark Prouty is President of Geometrics, Inc. in San Jose, CA. Prior to becoming President, Mark was Chief Technical Officer and Vice President of Engineering, beginning in 1994. Geometrics is a world leader in geophysical instruments including near-surface exploration seismographs, electromagnetic instrumentation, and magnetometers for exploration and UXO detection. Mark has been interested in improving the usability of magnetometers by designing systems to provide answers in real time, rather than data for post processing. Mark has led many well-known government-funded research programs, including the Advanced Ordinance Locator, (NAVEODTECHDIV), and many projects for SERDP and ESTCP, including: MetalMapper (MR-200603, winner of the ESTCP Project of the Year in 2010); Development of a Micro-Fabricated Total Field Magnetometer; (MR-1512, which won Project of the Year Award for 2008); Miniature Wideband Atomic Magnetometers (MR-1568); Enhanced EMI Processing (MR-1772); and Real-Time Magnetometer Array (MR-2104). Mark received his Ph.D. in Electrical Engineering from the University of California, Berkeley in 1994.
 

Dr. Thomas Bell is a Chief Scientist with Leidos Corporation in Arlington, VA. Tom’s current areas of research focus on adapting electromagnetic sensor technology to detect and classify unexploded ordnance (UXO) in marine environments. He has served as Principal Investigator on several successful SERDP and ESTCP projects to develop and demonstrate advanced electromagnetic sensors for detection and classification of UXO on land, one of which won the ESTCP Project of the Year award in 2014 (MR-200807/MR-200909). Tom has presented dozens of papers on UXO detection and characterization at various meetings and symposia which document his ongoing contributions to the UXO detection and discrimination problem. He has served as an instructor for SERDP/ESTCP short courses on Geophysical System Verification and on Classification for Munitions Response, and for the Naval Facilities Engineering Command’s Remediation Innovative Technology Seminar and the National Association of Remedial Project Managers Annual Training Program. Prior to his work with SERDP and ESTCP, he was engaged in basic and applied research in physical oceanography. He received a Bachelor of Science in Physics from the University of Maryland in 1969 and a Ph.D. in Geophysical Fluid Dynamics from the Johns Hopkins University in 1973.