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.