Targeting trouble in tough terrain

When you’re surrounded by potential enemies with lots of hiding places, it’s hard to anticipate when the next shot will come or from where. It’s a problem that the Defense Department has long worked to solve and has fielded a variety of solutions during the last 50 years.

But the challenges that have emerged in Iraq and Afghanistan have increased the urgency in developing technologies that can help warfighters in the field locate snipers, mortar teams and other immediate but low-intensity threats — particularly in Afghanistan, where mortar attacks in mountainous terrain are a frequent danger.

DOD has used radar-based systems to detect and target enemy artillery positions, including the Army’s Firefinder system. Firefinder is the basis of an anti-mortar system already deployed in Iraq and Afghanistan. The Integrated Base Defense System of Systems, largely built and integrated by Northrop Grumman, consolidates radar data from a range of other systems, including Northrop Grumman’s Counter Rocket Artillery and Mortar (C-RAM) arrays.

In some cases, especially at frequently targeted or sensitive locations, such as power stations, C-RAM is attached to a land-based version of the Navy’s MK 15 Phalanx Close-In Weapons System, which uses two 20-mm gun mounts. Each gun mount has six rotating barrels that are directed by a targeting radar system enclosed within a white dome on top of the gun emplacement.

Designed to destroy incoming missiles at close range, the guns fire exploding shells at either 3,000 or 4,500 rounds per minute. The Navy has been installing them on its ships since 1977.

C-RAM systems have raised incoming- round alarms more than 1,500 times since they were first deployed in 2003 and had shot down more than 100 incoming rounds as of March 2006, the last date the Army made such data available, said Tim Rider, spokesman at the Army’s Program Executive Office for Command, Control and Communications Tactical (PEO-C3T).

But the truck trailer-based Firefinder systems aren't mobile enough for the mountains of Afghanistan. For lighter, foot or motorized patrols under threat of mortars, the Army has deployed a portable system called the Lightweight Counter Mortar Radar (LCMR) from Syracuse Research Technologies Systems.

It uses Doppler radar to provide 360-degree surveillance for small incoming targets and sends a warning message when it detects one. As the round approaches, it collects trajectory data to track the round and identify the location from which the attack was launched on a 10-digit grid, with a designed accuracy range of as little as one meter. A variant can track small aircraft to a range of 18 kilometers.

There are more tactical and less data intensive — and less expensive — systems that locate snipers or mortar teams by sound. Systems such as BBN Technologies’ Boomerang use seven to 10 microphones on a pole to detect the sound of a shot and determine its location by triangulating differences in the sound picked up by each microphone.

Boomerang systems also feed data into Blue Force Tracking applications and the Force XXI Battle Command, Brigade-and-Below (FBCB2) network and can more precisely locate a shooter by comparing data from more than one system. More than 1,000 Boomerangs are currently deployed, most on Stryker and other armored vehicles.

BBN is working on a version called Boomerang Warrior that is part of the Land Warrior system, which is designed to equip soldiers on the ground with targeting and location data using tiny, lightweight electronics that display in a screen attached to a trooper’s helmet.

QinetiQ North America is developing a similar wearable acoustic system under a $10 million contract from the Army Rapid Equipping Force that is expected to deploy in Afghanistan in 2009. The Soldier Wearable Acoustic Targeting System units weigh 6.4 ounces, are attached to a trooper’s shoulder, and are designed to locate gunshots within a 360-degree radius within a second of the shot being fired.

Acoustics are one of many capabilities of the unattended ground sensors units that are part of the larger Future Combat Systems (FCS) development. UGS systems come in a range of configurations and capabilities from several contractors.

They can be small, cheap and expendable or larger and capable of detecting enemy movement using magnetic, chemical and radioactive sensors in addition to cameras and microphones.

The Army already uses non-networked versions of the UGS in Iraq and Afghanistan.

They’re largely designed to be dropped or placed in mountain passes, near roads or paths enemy troops are likely to use in the future, or around an established base.

Developing observation and reconnaissance technology is an important part of the Army’s new strategy, according to statements from Rep. John Murtha (DPa.), chairman of the House Appropriations Committee’s defense subcommittee.

After a demonstration of FCS technology at Fort Bliss, in 2008 he decided its capabilities should be sent to warfighters in the field as soon as possible.

FCS-equipped units can multiply the eyes and ears of a military force many times without risking the lives of any of its members, Murtha said.

Using that technology to enhance the Army’s ability to find snipers, mortar teams or other threats makes more sense than waiting for the full range of FCS systems to be complete years from now.

A range of ground-based robots are also designed to ferret out the location of shooters, including iRobot’s Robot Enhanced Detection Outpost with Lasers. The system is an acoustic and laserimaging system designed to be used on its PackBot remote-controlled robot, which is already deployed in Iraq and Afghanistan.

There are also a variety of acoustic and visual detection systems designed to be installed on vehicles, including the M1 Gunfire Detection System developed by the Army Research Laboratory, the Tetrahedral Gunfire Detection System from AAI, and Weapon-Watch, a vehicle-mounted system from Radiance Technologies that spots the heat signature of a weapon that has just been fired and raises an alarm.

However, DOD isn’t relying only on systems it has in development already. It is working with Northrop Grumman, Lockheed Martin and other major contractors on a range of detection and target-acquisition systems based on lasers, microwaves, small radar systems and nanotechnology.

The most advanced but least likely to become practical in the near term is “smart dust,” networked nanomachines designed to be so cheap and plentiful that they could be sprayed over hundreds or thousands of square miles.

Each smart dust mote might only have a range of a few meters, but each would be able to network with others nearby to relay messages.

Though the capability is attractive, it’s also unlikely to be practical for at least a decade.