Truck crews test anti-sniper acoustic sensors.

TO HELP DEFEND U.S. soldiers in Iraq from sniper attacks, the Army will be testing a prototype acoustic sensor that will be installed in a weapon-mounted Humvee truck.

Acoustic sensors detect, locate, and classify gunfire by sound. A Humvee--equipped with a weapon system that is remotely operated from inside the truck--will detect a sniper by the sound of the gunfire and target the weapon in the direction of the enemy shooter.

The acoustic system provides azimuth, elevation, range, caliber, miss distance and GPS location of sniper fire. Then, the weapon turret on the truck, called the common remotely operated weapons station, or CROWS, swings the thermal imager or day TV to the source of the fire for positive identification and targeting.

Program managers at Picatinny Arsenal in New Jersey say the technology could help save troops who are often targeted by insurgent snipers in Iraqi cities.

CROWS enables its operator to fire machine guns or grenade launchers accurately from the protection of the Humvee cabin rather than from an exposed turret. The system has a day camera and night thermal imager to identify targets at extended ranges on a gunner's display. A ballistic computer receives inputs from a laser rangefinder and barometric, wind, and temperature sensors.

Four CROWS prototypes were sent to Iraq in December 2003 and received positive reviews. The Army then ordered 259 additional systems. About 55 second-generation CROWS systems are now in Iraq with a mix of military police, cavalry, infantry and engineer units. Another 600 may be ordered in 2006.

The Army is considering an additional display to share sensor imagery with the vehicle commander. "The best way to survive an ambush is not to get into it," explains Lt. Col. Kevin Stoddard, product manager for crew served weapons at Picatinny. "The best sensors out there are more eyes on the battlefield; it makes a lot of sense to have both gunner and commander having use of the enhanced optics."

The acoustic sensor gives the vehicle crew "situational awareness," explains CROWS deputy product manager Richard Audette. "When a soldier is down underneath looking at a screen, he naturally loses some situational awareness."

Four CROWS systems with acoustic projectile detection and cueing sensors will go to Iraq in 2006 for operational assessment. The contractors selected for the project are Recon Optical and AAI Corporation.

Recon Optical buys the CROWS electro-optical sensors and computers from Fire Control Systems and EOS Technologies, which are U.S. subsidiaries of the Australian Electro Optic Systems, Ltd. AAI makes the acoustic sensors.

The operational CROWS system carries interchangeable 12.7 mm M2, 7.62 mm M240B, or 5.56 mm M249 machine guns, or the 40 mm MK 19 grenade launcher. With joystick commands, the weapons mount traverses through 360 degrees and elevates from -20 to +60 degrees.

The commonly used M2 heavy machine gun generates recoil forces of up to 1,000 pounds. "You're going to have a lot of shaking going on," says Audette.

While the current CROWS has been successfully integrated into Humvees, a lighter version is under assessment for use aboard medium trucks or other vehicles. Recon Optical has built six prototypes of the so-called CROWS "Lightning." It will be tested in Iraq in 2006.