New system locates origin of incoming fire

Soldiers and law enforcement personnel would be grateful if they could pinpoint the location from which an adversary or criminal is shooting at them. Well, for three years now soldiers in Iraq and Afghanistan have had help locating snipers. An acoustics ­system known as Boomerang, developed by BBN Technologies, in Cambridge, Massachusetts, determines the location of a shooter by sensing the blast at the rifle’s ­muzzle and the air pressure of the bullet as it whizzes past. Now BBN is ­taking the technology a step farther: it is building and testing a version for ­helicopters, which it hopes to ship next year.

IEEE Spectrum’s Steven Cherry writes that the U.S. military first began to deploy the system in Iraq in 2005. Today more than 1000 of the units are in Iraq and in Afghanistan. BBN claims that the systems detect 95 percent of all bullets that fly anywhere within thirty meters of their sensors, never ­mistaking some other loud noise for a bullet (compare BBN’s system to that developed at Waltham, Massachusetts-based Foster Miller, a subsidiary of Qinetiq: the system, called EARS, is based on a tiny acoustic sensor that is able to identify the distance and direction of a sniper fire within a fraction of a second; see 25 March 2008 HS Daily Wire).

In 1978 the U.S. Congress asked the company to analyze a ­motorcycle policeman’s audiotape of the 1963 ­assassination of President John F. Kennedy. “That was the point at which we started ­thinking about gunshots and gunshot ­detection via acoustic ­signatures,” says Dave Schmitt, BBN ­program manager for Boomerang. In the mid-1990s the Defense Advanced Research Projects Agency (DARPA) ran a small competition to pursue that line of inquiry, which BBN won. The United States was not involved in any hot wars at the time, “so they put that technology on the shelf,” he told Cherry. DARPA’s ­interest revived in the summer of 2003, when postinvasion resistance in Iraq led to frequent sniper attacks on U.S. troops. The agency asked BBN to build a system that would operate on the move. The company came up with a first-generation design in about two months, and 50 units were quickly assembled and sent over.

Using an array of seven microphones as its sensors, the system first detects the bullet’s supersonic shock wave, from which the system determines the angle from the sensor to the shooter. The system then listens for the muzzle blast.