Scientist develops land mine detection method from sound

ATLANTA (AP) -- Long after a war ends, the land mines left behind remain a deadly danger hidden from sight. But not from sound, researchers say.

Scientists at the Georgia Institute of Technology are developing a new system that shakes the ground to create sound waves and detect mines, even those that can't be found using traditional radar or metal-detection devices.

Systems using ground-penetrating radar fail because they can't tell the difference between mines and rocks, roots, cans or sticks, said Georgia Tech associate professor Waymond Scott. Metal detectors fail because they see every metal can, scrap and shell casing, resulting in a high false alarm rate.

Scott said the sound-wave techniques work because the mines, with air pockets, flexible cases and trigger mechanisms, reflect sound differently than other buried objects.