Wide-Area Assessment (WAA)
Description
Wide Area Assessment is a characterization
strategy using a variety of platforms to cost-effectively delineate areas where
unexploded ordnance (i.e., bombs and shells, or UXO) is likely to be found on
the vast munitions ranges throughout the United States. By narrowing the
footprint of potential UXO locations, WAA saves times and money on conventional
characterization.
Conventional detection and characterization
technologies involved hand-held magnetometers operated by technicians who must
slowly walk across a survey area, or using a towed array of sensors that is
driven across an area. These methods can be utilized more efficiently after
after high-level aircraft take high-resolution photographs to detect
topographic anomalies and low-altitude helicopters (flying about three meters
above the surface) delineate magnetic anomalies.
At underwater sites, high altitude aircraft are
not used; rather the area is subjected to both an assessment by low-altitude
helicopters and additional assessment by a marine towed arrays to detect
magnetic anomalies underwater.
Limitations and Concerns
No existing technology for characterizing buried
UXO achieves the 100% detection rate sought by many neighbors of military
property containing UXO, though they approach that for items on or just below
the surface. Wide Area Assessment is a tool that focuses on detecting areas
with high concentrations of munitions, not one single target.
Data interpretation is a key to the success or
failure of this technology.
Magnetic and electromagnetic detectors have
diminished accuracy in highly magnetic soils. High-density magnetic clutter can
make it nearly impossible to locate target areas.
Where vegetation exists or topographic anomalies
exist such that aircraft or towed arrays cannot be used, handheld magnetometers
must be used. Often the areas are so vast that this step does not take place.
Man-made alterations of the surface (or on the
surface) may obscure detection of UXO.
Physical access to a developed site may be
problematic (e.g., right of entry, fences, power lines, recreational activity).
Underwater UXO location does not have the same
level of confidence. In a marine environment, the distance between the array
and the targets will increase by the water depth, so only large munitions are
detected at any reasonable efficiency.
The tools used in Wide Area Assessment do not
replace the need for historical research.
Applicability
The U.S. Department of Defense (DoD) is
responsible for over 15 million acres of weapons ranges in the United States,
and over 1,500 sites may require the cleanup of UXO. Wide area assessment is an
advanced characterization technique.
Technology Development Status
Wide Area Assessment has been proven and is used
by the DoD. The marine systems are in the pilot stage of development.
Web Links
http://www.serdp-estcp.org/Featured-Initiatives/Munitions-Response-Initiatives/Wide-Area-Assessment
http://www.itrcweb.org/Documents/UXO-6.pdf
Other Resources and Demonstrations
http://www.serdp-estcp.org/Program-Areas/Munitions-Response/Underwater-Environments/MR-1631
http://www.serdp-estcp.org/Program-Areas/Munitions-Response/Underwater-Environments/MR-200606
See the descriptions of the Multi-Sensor Towed Array Detection System and MetalMapper.
See
also https://ert2.navfac.navy.mil/printfriendly.aspx?tool=mrpdetection.
See
also
http://t2.serdp-estcp.org/t2template.html#tool=energeticconstituents&page=Introduction
http://t2.serdp-estcp.org/t2template.html#tool=MRMT&page=IN
http://t2.serdp-estcp.org/t2template.html#tool=mrpdetection&page=Intro
http://t2.serdp-estcp.org/t2template.html#tool=mrpremoval&page=intro