PDCue

Another good listener is the Projectile Detection Cueing (PDCue) system, from the U.S. Army Armament Research, Development, and Engineering Center. The Army describes the PDCue 4-Corner System as a low-cost acoustic gunfire detection system that can detect and pinpoint the origin of incoming sniper fire. It's tied into the CROWS Lightning machine gun station mounted atop Humvees; the system supports both the M240 and M249 small arms weapons. The operator inside the vehicle can monitor and control both PDCue and CROWS Lightning from a single user interface.