Hand on the trigger: forward operating bases (and troops) are some of the most valuable and definitely the most vulnerable assets available to any commander. Keeping the front-line forces safe, and doing so without putting innocents in danger, requires an innovative mix of planning, equipment and technology.

A wide array of sensors and weapons are available to protect the forward-operating forces, but too often triggering some of these have caused some form of harm to innocents. Having a man in the loop who must make the final decision on unleashing a round or warhead takes the possibility of harming the wrong person out of the equation.

The selection of sensors varies from the Mkl Mod 0 human eyeball to acoustic, seismic, motion sensitive, thermal and magnetic. These can be located on or in the ground, on buildings, in trees or foliage, in the water or on a flying platform. Other force protection equipment can include stationary or active vehicle barriers, ballistic protection, active or passive surveillance and sensor arrays.

Taking Command

One remote system combines video in its surveillance loop to give the operator a positive identification of possible advancing threats. Textron Systems' Terrain Commander 2 is a covert, unattended early-warning surveillance system for detecting and identifying intruders. The sensors send activation messages to the system's Oasis2 (Optical Acoustic Satcom Integrated Sensor) base station which transmits data and images to protecting forces--with this information guarding units know whether to prepare for attack or simply allow advancing elements to pass.

The Terrain Commander 2 combines acoustic, seismic, magnetic, electro-optical and passive infrared sensors in custom configurations for front-line defensive position protection.

Textron Systems was awarded a contract in June 2006 from the US Project Manager Close Combat Systems to develop an Intelligent Munitions System (IMS) for the Future Combat Systems programme. The IMS combines battlefield intelligence with precision munitions to attack light wheeled and heavy tracked vehicles as well as enemy personnel.

The IMS features built-in self-destruct/self-deactivating and enhanced control facilities to provide the requisite detection, classification, tracking and engagement information in accordance with user-defined parameters. A Commander's Control Station (a PDA-type unit) provides a display of situational awareness from the IMS dispenser module sensors. This information provides for positive control over munition activation--allowing safe passage for friendlies and non-combatants, over-the-air transfer of system control, activation of anti-tank, anti-vehicle, anti-personnel or non-lethal munition or deactivation for safe munition recovery.

The IMS dispenser module includes onboard algorithms that process acoustic, seismic and magnetic data to detect, classify and differentiate between personnel and vehicles. Four Spider anti-personnel grenades protect the anti-vehicle munitions from tampering. Spider munitions are triggered by wireless control with the commander's hand-held PDA.

Land-based Falcon

In 2005 Harris Sensor Systems introduced its remote, unattended intrusion detection and surveillance system called the Falcon Watch. The system includes the RF-5405 Intelligent Gateway, which is a communication node that receives alarms from various sensors (the RF5400 Falcon II Sensor Node) and fuses that information for relay to the unit's operation centre.

Seismic, magnetic and passive infrared sensors are used to detect the movement of vehicles and personnel while the system filters out non-threatening and naturally occurring events. The modular, radio-based system processes the inputs at the point of detection and the resulting data is transmitted to the monitoring operator for clarification and action.

In June 2006 Harris signed a license agreement with Telonics of Mesa, Arizona, to incorporate that company's Eagle Intrusion Detection System Unattended Ground Sensor products and technology into the Harris Falcon Watch systems.

A Smart Lass

DRS Technologies provides its Lightweight Acoustic Sensor System (Lass) to the US Navy for its Mobile In-shore Undersea Warfare amphibious operations, as it is the primary sensor for undersea surveillance. The bottom-mounted array detects and provides acoustic threat data for monitoring surface ships, small boats, submarines, mini-subs and swimmer-delivery vehicles.

The rapidly deployed system has an operational depth of between 2 and 180 metres, is powered by a lead-acid battery that provides 21 days of continuous operation and features a solar panel for backup/extended power. The Lass transmits detection information to shore- or ship-based sites by either a VHF radio link on a surface buoy or through a hard-wired fibre-optic cable.

One other force protection system from DRS is the Integrated Sensor Command System (ISCS) that is designed to detect and identify surface, subsurface, swimmer, air, ground and human targets. A mobile command and control system is networked with its own and other sensors and assets and, through its automatic system of detection, tracking, operator alerts and target/incident management, provides a command centre from where a complete detection, surveillance, reaction system is operated.

Standard equipment of the ISCS includes a low-probability of intercept Scout (surface search) or Squire (land) radar, an integrated electro-optical subsystem with visual and infrared sensors, cots-based rugged workstations and voice and data communication equipment. The system is available in either a wheeled or tracked configuration.

Eye in the Sky

Surveillance is a key element of force protection but doing so using only troops is manpower intensive, particularly for large bases or in complex terrain such as urban areas. One solution is to provide a cost effective eye in the sky. The US Army's Persistent Threat Detection System (PTDS) is essentially a large balloon, known as an aerostat,which is tethered to the ground to provide a low-cost platform for surveillance cameras and other sensors to monitor a large area around high-value installations. The Aerostat can lift a 225-kg payload to an altitude of 2500 feet. The PTDS was first deployed to Iraq for trials in 2004.

In November 2006 the service awarded Lockheed Martin a $ 77.5 million contract for the PTDS for deployment in Iraq. <<Aerostat surveillance systems give the army the reliable and constant information and intelligence collection capability vital to protecting deployed personnel and high-value assets>> said Lockheed's Ron Browning. The aerostats, sensors, ground stations and mooring systems will be assembled and tested at Lockheed Martin's Defense and Surveillance Systems facility in Akron, Ohio. The system will be delivered to the army by mid-2007 and will subsequently be operated and maintained by Lockheed Martin Technical Operations. The army's Program Executive Office for Intelligence, Electronic Warfare and Sensors, Project Manager for Night Vision, Reconnaissance, Surveillance and Target Acquisition, and Product Manager for Robotic & Unmanned Sensors are managing the project.

Patrolling the Wire

To monitor the extensive perimeters of more than 40 air bases around the world the US Air Force relies on Northrop Grumman's Tactical Automated Security System (Tass), a modular, wireless system that can be transported to forward operating bases on two aircraft pallets. The Tass integrates active and passive infrared, bistatic and monostatic microwave, seismic, magnetic, breakwire, fibre and radio frequency sensors to monitor the perimeter of bases, using radio frequency transmission networks for reporting alarms, desktop, laptop and hand-held computers to process, report and graphically display alarm information and hand-held, vehicle-mounted and long-range thermal imagers to investigate intrusions. The sensors can pick up intruders out to 200 metres. Desktop computers are located at a central command location, while the hand-held monitor can be used by security personnel in fighting positions around the base.

Northrop Grumman Mission Systems has developed Tass Version 6, which connects a wider range of sensors and assessment devices into a more tightly integrated network. A significant new function is a warning of the launching of rockets, artillery and mortars and their predicted point of impact. One of the sensors, which is linked to the 'enhanced Tass' (eTass), is the Lockheed Martin Desert Hawk miniature unmanned air vehicle, developed for the US Air Force as the Force Protection Airborne Surveillance System (FPass). Operating at altitudes of 300 to 500 feet, the Desert Hawk transmits real-time video imagery of the perimeter and surrounding area to the drone's two operators. FPass units are being deployed to air bases in the Middle East and Afghanistan as soon as they are delivered to the air force. (Drones will be covered extensively in the Complete Guide that accompanies issue 3/2007.)

In November 2005 the US Marine Corps asked the US Air Force to manage the acquisition and deployment of a Tass to protect A1 Asad Air Base in Iraq. The system was in place in only 90 days and the US Marine Corps was so impressed that it has decided to make Tass its 'system of choice' for expeditionary electronic security, and in late 2006 asked for a system to be deployed to Al Taqaddum, Iraq. <<It has provided the marines [with] increased battlespace management and situational awareness at our bases in Southwest Asia,,, said a US Marine Corps official responsible for counter-terrorism and force protection. The systems being delivered to the marines come under the umbrella of the $ 498 million Integrated Base Defense Security Systems contract awarded to Northrop Grumman Mission Systems by the US Air Force Electronic Systems Center at Hanscom Air Force Base, Massachusetts in August 2003.

Incoming Fire

Insurgent mortar and rocket fire poses a threat to US and other coalition forces in Afghanistan and Iraq. Quick, accurate location of the firing position is a prerequisite to providing an effective response without inflicting collateral damage. In September 2006 PEO-IEW&S awarded a $120 million contract to Lockheed Martin to provide five Enhanced AN/TPQ-36 radars, which are also known as the EQ-36 Counterfire Target Acquisition Radar. The radars will be delivered before the end of 2009. The service has an eventual requirement for more than 180 EQ-36 radars, worth in excess of $1.6 billion, to replace ageing TPQ-36 and TPQ-37 systems. Lockheed Martin Maritime Systems & Sensors (MS2) is responsible for the transmit/ receive modules, the antenna array and the digital module assemblies. Other teammates include Syracuse Research Corporation, which is responsible for the digital signal processor, and Burtek, which will provide the operations shelter and stationary platform.

Another component of the American Counter Rocket, Artillery and Mortar system of systems is Syracuse Research's Lightweight Counter-Mortar Radar (LCMR), which was developed initially to the meet the requirements of the US Army's 75th Ranger Regiment for a man-portable system that could be deployed by parachute. The first LCMR was delivered in January 2004, and twelve months later more than 30 were deployed on operations. The tripod-mounted radar is carried in two 27-kg loads. The LCRM has the unique ability to locate firing systems through a full 360[degrees], as compared to most other in-service radars which can only view 90[degrees] or less at a time. The radar can locate firing systems to an accuracy of 100 metres out to its maximum range of 7000 metres and also predicts the point of impact. The LCMR was selected as one of the army's 'Top Ten Greatest Inventions' of 2004 and the Deputy Secretary of Defense listed it among the ten force protection initiatives required for Operation Iraqi Freedom. The LCMR has been deployed with army, marine and special forces in Afghanistan and Iraq. The army is seeking about 300 systems to deploy within its new modular brigade combat teams--for this application Syracuse is working to extend the range of the system from 6.5 km to about 10 kin. The fiscal year 2007 defence budget provides further funding to develop an LCMR Base Protection (LCMR-BP) system that links multiple LCMRs and other sensors into a comprehensive system.

Locating the Enemy

Snipers and other combatants who take advantage of cover and concealment are difficult to detect but there is a growing use of technology to enable soldiers to locate the source of small arms fire. Canada's MacDonald Dettwiler Associates began developing the Ferret acoustic detection system to detect sniper fire in the late 1990s, and the system has been successfully deployed on Canadian Army 8 x 8 Coyote reconnaissance vehicles and LAV Ill armoured personnel carriers in Afghanistan. The Ferret detects when rounds have been fired, from which direction they have been fired and provides the vehicle crew with a bearing. It can also identify the calibre of rounds between 5.56 mm and 7.62 mm. The microphones are attached to the short mast of the Goodrich AN/VVR-2 Laser Detecting Set, which is mounted on more than 700 Canadian LAV-series vehicles. The two companies have formed a teaming arrangement and Goodrich markets the two elements as the Acousto Optical Warning System. The Ferret has been supplied to the US Army's Tank Automotive Command and the US Marine Corps Systems Command for evaluation.

The US has fielded other small arms detection systems. The Department of Defense is seeking a 'cheap, cost effective' solution that could be fitted to every US military vehicle in an operational theatre. At the request of the Defense Advanced Research Projects Agency (Darpa), BBN Technologies developed and delivered 50 examples of its Boomerang sniper detection system in only 66 days in late 2003 for installation on US vehicles in Iraq. BBN designed a system that is based on non-linear algorithms that utilise both the sound of the muzzle blast and the supersonic shock wave of the bullet to pinpoint the firing position. The improved Boomerang 2 is now deployed in Afghanistan and Iraq on 100 vehicles and another 100 systems are being deployed to extend the field trials. Within one second of a shot being fired the Boomerang 2 can indicate the direction to the shooter to within 2.5[degrees] even when the host vehicle is travelling at a fast speed. The Boomerang 3 will soon be ready for deployment. Besides US forces the armies of Canada, Israel and France have expressed interest in the system.

Israel's Rafael has developed its Spotlite Mk II sniper detection system (as mentioned in the article "A Gold Mine of New Technologies" in this issue). The system's electro-optical sensors detect a muzzle flash out to one kilometre, then lock onto and track the subject. It sends this information to the spotter's Toughbook computer for positive identification, and then it is forwarded to a sniper, who is up to 300 metres distant, to engage the threat.

Through the US Foreign Comparative Test programme the US Special Operations Command purchased 154 Pilar Acoustic Vehicle Mounted Gunfire Detection Systems and 124 Pivot (Pilar Versatile Observation Turret) units from the French company Metravib. The Pilar is able to pinpoint firing points out to 1200 metres. The Pivot is a high-speed pan-and-tilt turret linked to the Pilar. When a shot is fired the Pivot control unit processes azimuth and elevation outputs to rotate and tilt the Pivot turret in the proper direction to provide a picture of a shot origin in real time. British forces are evaluating the Pilar in Iraq, Germany has ordered two ground-based systems for evaluation and Belgium has bought 75 systems to install on its new Mowag Piranha IIIs.

Small arms detection systems can be linked to vehicle turrets and remote control weapon stations to automatically slew the weapon toward an enemy firing point. There is a general consensus that in most circumstances, certainly in operations other than war, a man must remain in the loop to make the decision to return fire. The risk of causing casualties to friendly forces and non-combatants, and unacceptable collateral damage, is too great to remove the element of human judgement.

Spinning a Safety Web

Designed with close co-operation of the US Army Combat Engineers and the b Project Manager for Close Combat Systems (and as a replacement to persistent anti-personnel land mines in Korea), Textron Systems and ATK developed the Spider force protection system that combines remote command and control of lethal and non-lethal munitions. The system consists of three main hardware elements: lethal and non-lethal munition control units, a remote control and a repeater. The Spider is a true man-in-the-loop system, whereas the operator must make a conscious decision based on the rules of engagement to engage a target. The Spider uses a series of trip wires arranged in a spider web pattern out from the central unit (or units) and, as a wire is tripped, the operator makes a field observation of the Spider's location and determines if the intruders are friendly or not.

The operator can choose to allow passage, to fire a munition immediately or to allow a group to enter the kill zone and execute a delayed ambush. Following engagement the spent munition cartridges, trip wire modules and battery are replaced as required.