Lasers: The Battlefield Tools of Tomorrow Are Here
Buck Rogers technology has arrived four centuries ahead of schedule.
Lasers are entering the inventories of armed forces around the world. They are used as rangefinders, tar-get designators, position locators, small arms sights, communications devices, and even as weapons to destroy enemy sensor systems. Only a few decades ago, coherent light weapons were relegated to the realm of science fiction writing. Now analysts predict that lasers will soon be as common place on the battlefield as assault rifles and binoculars are today.
The most extensive present military application for lasers is in rangefinding. Laser rangefinders work on the simple principle that the speed of light is constant. They work as follows: a laser beam, aimed through optics, is directed at an enemy target at an unknown distance. A small fraction of this laser light is reflected back to the rangefinder. The transmission time is compared electronically with the return time of the laser light, yielding a highly accurate measure of distance. Typically, this distance is displayed by a light emitting diode (LED) digital readout that can be seen through the optics of the rangefinder. Thus, the operator can keep his eyes on his target.
Examples of contemporary tactical laser rangefinders include the AN/GVS-5, and the AN/PVS-6, also known as the mini eye-safe laser infrared observation set (MELIOS). The Army plans to buy as many as 4,000 MELIOS units. Unlike most earlier-generation rangefinders, MELIOS is eye-safe. This means that if human eyes are inadvertently lased by the device, there is no risk of retinal damage. The prime contractor for full scale engineering development of MELIOS is Optic Electronic Corp. (OEC), Dallas. OEC is also the prime contractor for AN/GVS-5. The company edged out the Hughes Industrial Products Group supported by the Hughes Electro-optical and Data Systems Group, El Segundo, Calif. According to an OEC spokesperson, the company's MELIOS prototype uses an Erbium rod laser operating in the 1.54-micron range. OEC's prototype is claimed to be effective up to 10 kilometers, and to provide update ranges every three seconds. The spokesperson said that the Hughes candidate for MELIOS used neodymium-doped yttrium aluminum garnet (NdYAG) laser technology and Raman-shifting to bring their laser beam into the eye-safe range of the spectrum.
Laser rangefinders are also commonly mounted on most modern tanks built in both the West and the Warsaw Pact nations. The laser rangefinder for the M1 tank, for example, can accurately measure range from 200 meters to almost 8,000 meters. It uses a NdYAG laser rather than a traditional ruby laser to reduce power consumption, and features built-in test equipment. The 20-pound unit is mounted in the commander's cupola (demiturret) of the M1 and M1A1 tanks. The current rangefinder will likely be superseded by a more capable carbon dioxide (CO2) laser range-finder. This new system is being developed by the team of GEC Avionics, Atlanta, and Kollsman Military Systems Division, Merrimack, N.H. In August 1987, the two companies received a full-scale development contract for the new CO2 rangefinder. The Army plans to procure at least 4,000 of the new lasers, one for each of its planned inventory of M1A1 tanks.
Laser target designators differ from laser rangefinders in that they "paint" or "lase" targets with a much more powerful beam. With most contemporary systems, these beams are also specially encoded. With this coding, laser-guided weapons can lock onto a target, and distinguish it from other targets that might be simultaneously designated by other systems.
A variety of weapons can home in on targets being painted by a laser target designator. These include the Hellfire missile, the laser-guided variant of the Maverick missile, the Copperhead 155mm artillery projectile, the Merlin mortar projectile, and a variety of laser-guided bombs. The accuracy of these weapons has been well documented. Laser-guided bombs, also called "smart bombs," were first used extensively in the Vietnam conflict. They were typically employed against large fixed targets such as bridges. While a propeller-driven observer aircraft carrying a laser target designator circled the target and "painted" it, a single jet-powered attack aircraft would approach and release a single laser-guided bomb to destroy the target. Previously, entire squadrons of attack aircraft carrying dozens of traditional "dumb" iron bombs had been used against the same targets with only mixed results. The overwhelming success of these early "smart bomb" missions ensured continuing development of both laser-guided weapons and laser target designators.
Two varieties of laser target designators are most commonly used by U.S. forces. Both are built by the electro-optical and data systems group of Hughes Aircraft Co., El Segundo, Calif. The first is the ground/vehicular laser locator designator (G/VLLD) also known as the AN/TVQ-2 or "Glid." The G/VLLD is a large, powerful laser target designator weighing about 50 pounds. It is normally tripod-mounted.
The other system in common use is the modular universal laser equipment (MULE), or AN/PAQ-3. The MULE weighs 38 pounds, and can be handheld or tripod-mounted. According to an industry expert contacted by DE, a new version of the MULE is being developed under an Army product improvement program (PIP). The PIP version of the MULE will weigh only 21 pounds. The source said that the lightweight MULE is being developed to fill the requirements for the U.S. Marine Corps and special operations forces.
Another category of equipment similar to laser designators are laser markers. In general, laser markers put out a less powerful and less precise beam than laser target designators. Most laser markers can be used to designate only large, fixed targets. In contrast, laser designators can be used to pinpoint both fixed targets and small and/or moving targets.
As new generations of more capable equipment are being procured, the distinction between laser markers and laser target designators is becoming blurred. At least one laser marker now in development could also be termed a laser target designator. This confusion over terminology also has an impact on proponent agencies. The Army's proponent agency for laser target designators is its Missile Command (MICOM) at Huntsville, Ala. However, the Army has a separate proponent agency that controls development of laser markers, its Night Vision Laboratory, part of the Communications-Electronics Command (CECOM) at Fort Monmouth, N.J. Conceivably, a military organization developing a requirement for a laser aiming device could have the choice of choosing which agency will be its proponent, simply by calling the device that they need either a "laser designator" or a "laser marker."
One of the most interesting applications of lasers to ground combat is their usefulness in sighting small arms. This technology was first developed for law enforcement, but has now been picked up by the military. One of the first successful applications of laser sighting was the American 180, a submachine gun made by Voere GmbH of Austria that was first imported in the late 1970s by Christopher and Associates, Glendale, Calif. The American 180 fires the diminutive .22-caliber long rifle cartridge at a cyclic rate of more than 1,200 rounds per minute. With a magazine capacity of 177 rounds, and its high cyclic rate, the American 180 is an effective weapon at close range. What makes the American 180 special is the bulky battery-powered laser mounted coaxially beneath the gun's barrel. The laser projects a red dot that corresponds with the point of impact of the bullets fired by the gun at a pre-set range. The dot can be seen both day and night.
Law enforcement officials quickly grasped the potential of the laser-sighted American 180. For example, several state prison systems bought the weapon because of both its physical its and psychological value. They reported that when the laser was scanned over crowds of prisoners engaged in large scale brawls, the fights immediately ended, and the prisoners became remarkably calm. Officials noted that the convicts realized that wherever the red dot landed, instant death could follow with a squeeze of the trigger. Since the American 180 was introduced, laser aiming lights have become much more compact. In fact, several firms now offer devices small enough for use with handguns.
A more sophisticated laser aiming system is the AN/PAQ-4 laser aiming light. The AN/PAQ-4 can be mounted on a variety of small arms. To date, the U.S. military has procured mounts for the M-16 rifle/M-203 grenade launcher, the AT-4 anti-tank missile launcher, and the M-60 7.62mm NATO light machine gun. The effective range of the AN/PAQ-4 is only about 100 meters. According to an announce-ment in Commerce Business Daily, there are developing requirements in the Army for a more powerful replace-ment for the AN/PAQ-4. This replacement would be mounted on longer-range weapons such as the M-60 light machine gun and the venerable M-2 .50-caliber Browning heavy machine gun. The AN/PAQ-4 follow-on would be effective to about 1,000 yards, the announcement said.
When combined with "starlight" electronic light amplification night vision equipment, laser aiming lights can be very effective. Some laser aiming lights, such as the AN/PAQ-4 emit light that is not visible to the naked eye. The PAQ-4 emits an infrared beam that can only be seen through night vision goggles (NVGs) or infrared viewers. Typical NVGs include the AN/PVS-5 and the later generation AN/PVS-7. The AN/PAQ-4 uses a gallium arsenide (GaAs) laser diode powered by a battery to produce its beam. The light emitted is in the far infrared spectrum (at about 9 microns).
Analysts predict that the simultaneous application of laser aiming and NVG technologies will doubtless make newspaper headline sometime in the future. One market analyst contacted by DE described a potential scenario for their employment: "Picture a special operations unit like the .U.S.) Army's Delta team. Special Forces Operational Detachment D) or the British SAS going into some two-bit Third World country to rescue a group of hostages being held by terrorists. The Delta team members would be carrying weapons like HK MP-5s .a 9mm submachine gun manufactured by the West German firm Heckler und Koch GmbH). These guns would be equipped with both suppressors .more commonly called silencers) and laser aiming lights. They would also wear night vision goggles so that they could go into a location where hostages are being held in almost total darkness. The guards would not even be able to see them. However, the assault team would be able to see the guards very clearly through their NVGs. They would also be able to distinguish the hostages from their captors. With infrared laser aiming lights, they could project dots on the head or chest of the guards that would be clearly visible to them .the attackers), but invisible to the guards. With suppressors, the sound of their weapons would not carry more than two or three hundred yards, at most. Suppressors would also eliminate virtually all of their gun's muzzle flash. Under these circumstances, any return fire would be like trying to hit a ghost with a sword. It would be absolutely no contest."
The communications field also holds potential for laser applications, although less well developed than weapon sighting. Communications systems using laser beams could potentially provide secure point-to point communications for tactical ground units. Unfortunately, there are a few drawbacks. First and foremost, they require a line of sight between transceivers. Second, they could be blocked by smoke or dense fog. Third, they might be detected by enemy sensors. Because of these drawbacks, point-to-point optical laser communications will probably not be used extensively on tomorrow's battlefields, except for a few applications where their benefits will outweigh their shortcomings.
It is predicted that the biggest contribution to battlefield communications that lasers will make will come from semiconductor lasers used to drive fiber-optic communications systems. As previously noted in DE, (May 1988, p. 19), fiber-optic cable systems will likely eventually replace tradi-tional "hard-wire" field telephone systems and other current communications systems that are dependent on copper wire or cabling.
One application for lasers on the battlefield that is often overlooked is in positioning systems. Systems such as the modular azimuth positioning system (MAPS) being built for the U.S. Army Material Command (AMC) use a ring laser gyroscope to provide inertially-derived positioning data. Two of the three full-scale engineering development (FSED) prototypes for MAPS used ring laser gyros, while the third, which was later dropped from the competition, used a traditional mechanical gyroscope.
Systems such as MAPS are used to update the current position of a vehicle or aircraft. According to a spokesperson with Honeywell Federal Systems (formerly Honeywell Aerospace and Defense), McLean, Va., Honeywell's MAPS entry was selected over one offered by Singer-Kearfott, which also used ring laser gyro technology. The third candidate, which was withdrwan, was offered by Litton. Honeywell's Military Avionics Division, Clearwater, Fla., received a 5-year, $5.7 million production contract for 27 MAPS systems in February. This contract was issued by the AMC's Picatinny Arsenal, Dover, N.J. Honeywell officials said that if all of the options to this contract are exercised, the Army could buy as many as 2,100 MAPS systems. The value of these options exceeds $250 million.
Honeywell's Clearwater operation also produces a missile guidance package for the Army tactical missile system (ATACMS) which also uses a ring laser gyro. According to a Honeywell spokesperson contacted by DE, the ATACMS guidance system has proved to be extremely accurate. "Even without terminal guidance, we are driving stakes with it," the spokesperson said. The same Honeywell division also builds a ring laser gyrobased navigation system for the U.S. Air Force. This system, called the Air Force standard navigator, is a form, fit and function replacement for traditional "iron" gyros. In addition to their capability in providing inertial positioning, ring laser gyros are also being examined for use in stabilizing weapons systems while vehicles are on the move.
PHOTO : U.S. Army Special Forces soldier at Port Bragg, N.C., employs an AN/PAQ-4 laser aiming
PHOTO : light mounted on a Colt M16A2 assault rifle. He is wearing AN/GVS-5 night vision goggles,
PHOTO : which allow him to see the otherwise invisible infrared dot projected by the laser
PHOTO : aiminglight.
PHOTO : One of the laser target designators in common use by the Army and Marine Corps is the
PHOTO : AN/PAQ-3, also known as the modular universal laser equipment (MULE), shown here mounted
PHOTO : tripod. It can also be hand-held.