New Technology Uses Sound to Find Land Mines

Bijal P. Trivedi
March 6, 2002

The U.S. Army is testing a new technology for land mine detection that is based on the use of sound waves. Officials say it could prove to be significantly more effective and safer than the best tools now available, metal detectors and titanium probes, which entail prodding gingerly for the presence of mines.

"Manual de-mining—direct probing of risky areas, inch by inch—is a very slow, difficult, dangerous, and laborious process. But it has been the only reliable method," said Jim Prudhomme of the United Nations Mine Action Service in New York.

Mine-ridden land must be stripped of all vegetation and searched with metal detectors. When a potentially dangerous object is found, it must be carefully unearthed. If it turns out to be a mine, it must be disarmed.

According to experts in the field, dogs have been particularly effective in locating land mines in Afghanistan, but their ability to detect mines is highly dependent on the soil conditions and they are susceptible to fatigue.

The extent of the land mine problem is daunting. There are an estimated 60 to 70 million land mines buried in about 70 countries throughout the world. Mines kill or maim more than 26,000 people every year, according to the United Nations Association of the USA.

"A metal detector works very well. But in the last few years the metal casing has been replaced with plastic and wood, which makes mines much more difficult to detect," said a physicist at the Night Vision and Electronic Sensors Directorate (NVESD) of the U.S. Army, based at Fort Belvoir, Virginia. The Army requested that the scientist not be named.

Greater Accuracy

The new acoustics-based technology, which is being developed by Stevens Institute of Technology in Hoboken, New Jersey, has advantages over other mine-detection advances now on the drawing board.

Much of the newer technology under development—including metal detectors, infrared imaging, ground-penetrating radar, and nuclear quadrupole resonance—has a fairly high rate of false positives, Prudhomme explained. That is, they regularly mistake common objects such as tree roots, rocks, shrapnel, bullets, and other debris as mines.

"That's the advantage of the acoustic system developed by the Stevens Institute of Technology," said the Army physicist. "It is sensitive only to mines and is not fooled by natural clutter, like rocks and tree roots, at least to the extent that we have tested."

In Army field tests last year, the new system successfully identified seven types of mines buried in different soil types and under different weather conditions. "The mines were detected successfully 100 percent of the time with no false alarms," said Stevens physicist Dimitri Donskoy, who designed the new technology.

"It looks extremely promising," the NVESD physicist agreed.

Continued on Next Page >>


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