Engineer showcases first remote explosive detection system based on sound

The first remote acoustic detection system to identify homemade bombs was showcased on Oct. 23 at the American Society of Mechanical Engineers Dynamic Systems and Control Conference in Stanford, Calif.

"Existing methods require you to get quite close to the suspicious object," Vanderbilt Distinguished Professor of Civil and Environmental Engineering and Engineer Douglas Adams said. "The idea behind our project is to develop a system that will work from a distance to provide an additional degree of safety."

The development of the detection system is part of a $7 million research initiative funded by Office of Naval Research grant N00014-10-1-0958 and led by North Carolina State University. Adams, Christopher Watson and Jeffrey Rhoads of Purdue University and John Scales of the Colorado School of Mines worked together on the acoustic detection unit.

The novel system uses a phased acoustic array and a laser vibrometer. The acoustic array can focus a strong sonic beam at an object while the laser vibrometer records its vibratory rate.

The rate of vibration is very telling of the object's contents. The unit can distinguish between low-yield and high-yield explosives.

"We are applying techniques of laser vibrometry that have been developed for non-destructive inspection of materials and structures to the problem of bomb detection and they are working quite well," Adams said.