AN/AVR-2B Laser Detecting System
Gourley, Scott R., Army
The broad mandates of warfighter survivability extend far beyond the recent proliferation of improvised low-tech/high-concept weapons. Just as the warfighters themselves must be prepared to operate across a broad spectrum of conflict, survivability planners must also address threats across the technology spectrum.
Regardless of whether a combat system is integrated into a ground- or aviation-based platform, one underlying essential to battlefield survivability is situational awareness.
Attempted threat action against any platform must be quickly detected, correctly declared and effectively communicated. The warfighter requires these outputs to respond with the correct countermeasure or battle drill. Without them, crewed platforms are rendered combat ineffective, if not completely destroyed.
Nowhere is that fact truer than with rotary-wing platforms. Although relatively immune to some of the current roadside threat devices, combat helicopter platforms and their crews face the potential of more technologically sophisticated threats.
One of these helicopter-threat categories involves laser-aided weapon systems, which can be categorized into three groups: rangefinders, designators and beamriders.
Rangefinders provide range and/or tracking information about the helicopter to a fire-control system. The system fires a short-pulsed, narrow beam onto the target, with the reflected signal then measured for time and position. As one aspect of the global proliferation of laser-aided threats, rangefinders increasingly are being incorporated in conjunction with antiaircraft guns to increase their probability of kill against low-flying tactical helicopters. For a gun system, the addition of a laser rangefinder can improve accuracy as much as 300 percent. In addition to the gun aspect, more sophisticated air defense systems may employ laser rangefinders to control the launch of multiple missiles.
Laser designators, the second group of weapon systems, use a laser source to continuously illuminate a target, with the surface-to-air munition acquiring and locking onto the reflected energy. Both sources and seekers of these weapons may be programmed for beam modulation, a process equating to a "code of the day," which keys the seeker and designator to reduce chances for decoying.
Beamriders, the third group of laser-aided weapon systems, employ a laser guidance beam to steer the missile. The operator uses a stabilized sight to track the target throughout the missile's flight, with a projected laser beam that scans the target to form a guidance corridor, which the missile uses to maintain a center position relative to the aiming point.
According to Raymond Trent, a program manager at Goodrich Corporation's ISR Systems, laser-aided weapon systems are becoming increasingly prevalent on today's battlefields and portend similar prevalence on battlefields in diverse geographical regions around the world.
"These systems use the unique properties of a laser to increase targeting effectiveness and hit probability," Trent explained. "The application is quite simple: An infrared laser beam is reflected on a target to accurately deliver a killing blow by some form of munition. The narrow, short-wavelength beam is usually fired in pulses or small bursts. This improves accuracy and reduces the lasing platform's susceptibility to detection.
"Because of their unique capabilities, laser-aided weapons are produced and fielded worldwide," he added. "They are commonplace in current operations and range from small arms to artillery systems, with ranges exceeding 20 kilometers. Laser technology has been successfully applied to a wide variety of weapons, resulting in significantly improved hit probabilities and engagement ranges, as well as overcoming limitations such as line-ofsight firing. Growing in sophistication, these weapons are accurate, affordable and extremely lethal. With thousands of units fielded, they are likely to be encountered anywhere hostilities occur. …