Boomerang ( countermeasure ) Boomerang is a gunfire locator developed by DARPA and BBN Technologies primarily for use against snipers . Boomerang is mounted on mobile vehicles such as the Humvee , Stryker , and MRAP combat vehicles . There were plans to integrate it into the Land Warrior system . Development . Boomerang grew out of a program conceived by the U . S . Department of Defense in late 2003 , months after the traditional combat phase of the Iraq War had ended on 1 May , at a time when it was clear that U . S . troops were increasingly at risk from a growing and aggressive insurgency . Often , troops in noisy Humvees did not know they were being shot at until someone was hit . U . S . Defense Secretary Donald Rumsfeld approached DARPA and asked for near - term solutions that could be applied to the conflict in Iraq . Rumsfeld was looking for something that did not have to be a perfect solution , but was at least better than nothing . The U . S . Army and Special Operations Command began using a limited number of French - made PILAR anti - sniper systems in 2003 , but at $ 65 , 000 per copy was too expensive to field in great quantities . This led DARPA to develop a new , more affordable system . Karen Wood , a program manager at DARPA , said BBN ' s previous work was the most impressive that was examined . BBN had previously developed a less sophisticated counter sniper system named " Bullet Ears " under DARPA sponsorship in 1997 . The new requirements included : The first prototype was developed in 65 days . Challenges to overcome were filtering out noise from the vehicle on which it is mounted ( such as loud engines and static sounds from the radio ) , ignoring sounds similar to that of a gunshot ( such as fireworks or a car back - firing ) , factoring in bullet ricochets , and ignoring outgoing fire from friendly troops . Small quantities of Boomerang were battle tested in Iraq and further improvements led to 2nd and 3rd generation versions called the Boomerang II and Boomerang III . In June 2008 a $ 73 . 8 million firm fixed price contract was awarded by the U . S . Army to BBN for 8 , 131 Boomerang Systems , spares and training services . In 2005 Boomerang won both the DARPA “ Significant Technical Achievement Award ” and the Massachusetts Innovation and Technology Exchange ( MITX ) " Technology Influencer of the Year Award . " Boomerang does not claim to be able to detect shots fired from firearms with sound suppressors . Operation . The Boomerang unit attaches on a mast to the rear of a vehicle and uses an array of seven small microphone sensors . The sensors detect and measure both the muzzle blast and the supersonic shock wave from a supersonic bullet traveling through the air ( and so is ineffective against sub - sonic ammunition ) . Each microphone detects the sound at slightly different times . Boomerang then uses sophisticated algorithms to compute the direction a bullet is coming from , distance above the ground and range to the shooter in less than one second . Users receive simultaneous visual and auditory information on the point of fire from an LED 12 - hour clock image display panel and speaker mounted inside the vehicle . For example , if someone is firing from the rear , the system announces " Shot , 6 o ' clock " , an LED illuminates at the 6 o ' clock position , and the computer tells the user the shooter ' s range , elevation and azimuth . Boomerang works in extreme weather , in open field and in urban environments , whether static or moving . BBN states that false shot detections are less than one per thousand hours of system operation at vehicle speeds under 50 miles per hour . Related development . Starting in 2011 , the US Army began issuing the Individual Gunshot Detector ( IGD ) which is similar to the Boomerang in function and purpose , but is worn by dismounted soldiers .