Technology That Locates the Origin of Sniper Fire

Making decisions in battle, Prussian military strategist Karl Von Clausewitz wrote two centuries ago, is akin to making life-or-death choices "in a mere twilight" with one's surroundings shrouded by the "effect of a fog or moonshine." In today's military jargon, it's called "poor situational awareness." Soldiers under fire express the idea with a simple question: where exactly are these bullets coming from? In urban battlefields in Afghanistan and Iraq, where locating a shooter by ear can be difficult amid the din of traffic and gunshot echoes, sniping has proved to be an effective tactic against soldiers from the United States and elsewhere. In both places, insurgents "had the run of things until we got smart," says John Plaster, a former major in the U.S. Army Special Forces and author of a sharpshooting manual and two histories of sniper warfare.

Getting smart means deploying countersniper technology. A handful of defense contractors have been developing sensors and computer systems that can locate shooters moments after they pull the trigger. Since many systems are in advanced development stages and have been tested in limited battlefield conditions, effectiveness is hard to quantify. But by many accounts, enemies tend to see countersniper gear as an infuriating and destabilizing turn of events.

The principles are straightforward. Since a rifle bullet flies faster than sound, precision microphones can detect its miniature sonic boom and calculate the projectile's origin. The sound of the muzzle blast, which arrives an instant later, provides additional data on the bullet's trajectory. In a few seconds, soldiers are informed with an audio alert of the shooter's direction, distance, elevation and, with some systems, type of weapon.

Police now use bullet-tracking technologies to help monitor 33 U.S. cities. (A dozen microphones, networked to a computer, can gather intelligence over three square kilometers. In all, about 250 square kilometers are monitored in this way.) For military applications, however, the goal is to help soldiers neutralize attackers. Many systems—including the PDCue, a sniper-location system made by AAI Corp. in Hunt Valley, Maryland—display location information visually on vehicle computer monitors or electronic devices carried by individual soldiers. Some systems, including Boomerang, made by BBN Technologies of Cambridge, Massachusetts, automatically direct weaponry—typically vehicle-mounted machine guns—to aim at shooters. (Conventional rules of engagement require that a soldier pull the trigger.) About 5,000 units have been deployed in Afghanistan and Iraq.

Some sniper-location systems use swiveling cameras to take live video footage of snipers' nests. Pilar, a system developed by 01dB-Metravib in Limonest, France, displays the video, in real time, on a computer screen. This winter a new model will stream video to small electronic devices carried by soldiers. The Pilar system is pricey, costing roughly €40,000. Even so, sales executive Philippe Sombstay says, "We're in the middle of a boom." Pilar has sold its gear to the armed forces of the United States, Belgium, Britain, France, Germany and Poland.

The next wave of devices promises to be smaller and more capable. QinetiQ of Farnborough, Britain, is supplying the U.S. Army with gunshot localizers called SWATS (Soldier-Wearable Acoustic Targeting Systems). Each weighs only about as much as several cigarette packs and is mounted on a soldier's shoulder. About 1,000 units, at roughly $10,000 apiece, are expected to be deployed in Iraq and Afghanistan early this year. A U.S. Air Force system called GSAT, now being developed by the American defense contractors Boeing, Insitu and ShotSpotter, incorporates an unmanned aerial vehicle, or drone. Radio transmissions of shooter coordinates are sent to the drone, which trains a belly-turret telescopic camera on the enemy and relays the video back to soldiers on the ground.

The next challenge is to locate snipers even before they shoot. San Diego-based Torrey Pines Logic has designed the Mirage 1200, a $40,000 "retro-reflection" handheld device that resembles large binoculars. It sweeps its field of view with eye-safe lasers to detect the tube of lenses on rifle scopes, even at night. Another version, which pivots from a stationary mount, scans for emplacements and weaponry, and streams video information to a nearby laptop, or via satellite to an operations room halfway around the world. The Mirage is now used in the battlefield, though for security reasons the company won't say which nation's military is using it, or where.

Some insurgent snipers have begun experimenting with countermeasures, using silencers to reduce noise and suppressors to slow down bullets, eliminating their miniature sonic boom. These steps reduce a gun's accuracy, range and lethality, however. Some sharpshooters have been able to get around countersniper systems that detect muzzle flashes with infrared sensors by taping heavy cloth bags over their barrels. Technologists are countering that technique with thermal sensors that assess the lightning-quick growth, size and disappearance of the hot blasts, or "blooms," that emanate from the barrels. For snipers combating technologically advanced armies, the business of warfare is now becoming appreciably more hazardous.