Development and Demonstration of a Handheld, Broadband Electromagnetic UXO Sensor
MR-200036
Objectives of the Demonstration
In 1998, the Defense Science Board (DSB) estimated that it would require $15 billion to clean up only 5% of the sites contaminated with unexploded ordnance (UXO) and, with the current practices, 75% of funds would go toward excavation of benign objects (i.e., false alarms). A major recommendation presented by the DSB was to reduce the false alarm rate for UXO by a factor of 10 within the next decade. Discrimination is central to reducing the false alarm rate for UXO, and this project sought to enhance UXO discrimination.
Technology Description
Magnetometers and metal detectors are used widely for ordnance detection. Magnetometers detect only ferrous metals that are contained in most munitions. Metal detectors detect all metals, ferrous and nonferrous. A magnetometer is a passive sensor that uses the static earth's field as its source, while a metal detector generates its own varying electromagnetic (EM) field. The sensor improved in this project is a combination of the GEM-3 hardware and electromagnetic induction spectroscopy (EMIS). The GEM-3 measures the broadband EM spectrum over a buried target, and the EMIS software attempts to identify the target by matching the observed spectrum with those spectra stored in the library for known UXO targets.
Demonstration Results
The broadband EM sensor improvement and demonstration undertaken in this project took the prototype GEM-3 and evolved it into an operational sensor with increased bandwidth and dynamic range and with enough memory and processing power to allow efficient data acquisition while decreasing the weight for ease of operation. In addition to the original handheld configuration specified at the outset, a cart-mounted large-coil configuration also has been developed for surveying large open areas. Specifically, the frequency range was doubled from 24 kHz to 48 kHz; 24-bit ADC replaced the 16-bit ADC, providing 48 dB of increased dynamic range; digital signal processor allowed continuous operation at more than 10 frequencies simultaneously; and compact-flash memory accommodated internal storage of data from a day of surveying. Performance in moguls and woods was not consistent with prior experience with detection capability of the handheld GEM-3, and the project team believes a problem with the target geo-referencing may have occurred. Detection performance was more reasonable in other areas, but discrimination capability has yet to be realized.
Implementation Issues
Further improvements may help achieve a discrimination capability for this system, including an increased range capability for detection of deeper targets and improved detection channel algorithms and discrimination algorithms. The ultimate goal is to help lower the extensive UXO cleanup cost for military lands through enhanced UXO discrimination. (Project Completed - 2006)
Project Documents
Points of Contact
Principal Investigator
Dr. I.J. Won
Geophex, Ltd.
Phone: 919-839-8515
Fax: 919-839-8528
Project Documents
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.