Army Tests New Acoustic Threat Detection System

The U.S. Army is experimenting with acoustic threat detection systems to help soldiers in combat zones pinpoint the location of incoming fire, from automatic weapons to rocket-propelled grenades, officials said.

The service is testing products including FireFLY, which was used in Afghanistan for a two-year period through 2013, and a newer and bigger system called Serenity, which is works with infrared cameras to produce more precise geolocation data.

"It's not an official program of record, but it's based off of 10 years of research and it's in the late prototyping stage," David Anderson, president of Invariant Corp., said last week during an exhibition at the Pentagon to showcase various military research projects.

The company teamed with Hyperion Technology Group to develop the technology in collaboration with the Army Research Lab and the Army Aviation Research, Development and Engineering Center, known as AMRDEC.

Serenity, made by Logos Technologies LLC, builds upon technology developed for the FireFLY ground system and integrates data from both electo-optical and acoustic sensors to increase accuracy and reduce false alarms. It features a six-microphone array and eight-sensor camera pod that can be mounted on a blimp or radio tower to detect threats such as rocket-propelled grenades and detonations up to 10 kilometers away.

"The infrared looks for a flash from a gunshot and the acoustics listens for the bang," said Geoffrey Carter, president of Hyperion. "So we get the flash and the bang, and then we cue the operator. The accoustics get us very accurate azimuth, or bearing, to the threat. The combination of knowing the speed of light and the speed of sound, we're able to get the distance in the time of arrival to the threat."

The product is designed to be installed around the perimeter of a contingency operating base, or COB, or forward operating base, or FOB, where troops can have limited situational awareness, Carter said. "They hear gunshots but they don't always know where they're coming from," he said. "So this gives them very pinpoint geolocation where the activity is coming from."

A typical configuration for FireFLY costs around $45,000, while the bigger Serenity system goes for about $400,000, officials said. (Images of the latter weren't immediately available.)