thedrifter
02-27-07, 08:52 AM
Hunting the hunters
Defeating enemy snipers hinges on sensor technology and marksmanship
By Paul Richfield - Staff writer
Posted : March 05, 2007
Well-aimed rifle shots from enemy sharpshooters are second only to roadside bombs when it comes to inflicting casualties on coalition forces in Iraq. Not only have these sniper-style attacks become more frequent and brazen, the insurgents also have taken to videotaping them for propaganda value.
These videos, which are easily accessed on the Internet, reveal the brutal reality of contemporary guerrilla warfare. The victims are typically U.S. soldiers or Marines in the midst of routine duties, seemingly oblivious to the danger they face. Several videos show the shooting of troops standing in the rooftop hatches of Humvees or manning checkpoints. One depicts the killing of a soldier walking on a highway, with the unarmed medic who rushes to his aid shot, as well.
“These attacks do damage, but their greater impact is the ability to spread the terrorist message to a global audience,” said Mark Spicer, a retired British army sergeant major and longtime sniper instructor. “With the videos, the insurgency gets a fantastic return for a very small investment of men and material.”
In many cases, the perpetrators of these acts can not be considered snipers in the traditional sense, because they strike from relatively short ranges with common assault rifles, such as the Russian Kalashnikov AK47. Intelligence officers say they believe the most popular weapon among insurgent snipers in Iraq may be the “Tabuk,” an Iraqi-produced AK47 clone furnished with a lengthened barrel and a low-power telescopic sight.
The insurgency has also employed several versions of the SVD Dragunov, a semi-automatic sniper rifle built in large quantities by the former Soviet Union and its client states, as well as Iraq under Saddam Hussein.
Needless to say, eliminating enemy snipers is a top priority among coalition forces in Iraq. The Army and Marine Corps, for example, are ramping up their sniper and long-range marksman training programs to speed the flow of trained personnel to the war zone without a reduction in quality. And technology designed to reveal the locations of enemy snipers, long in development, is beginning to appear in the field.
Such countermeasures work by detecting the firing of a shot, with the goal of estimating the bullet’s trajectory and tracing it to the sniper’s location. Once the sniper’s location is revealed, it may be subject to countersniper fire, mortar attack or even an airstrike with precision-guided weapons. These firing-related phenomena include the sniper rifle’s muzzle blast and flash; the shock wave, vortex and thermal signature generated by the bullet in flight; and the reflection of light off a telescopic sight or other optical device.
Muzzle blast and flash occur as the bullet leaves the rifle barrel. Acoustic sensors can detect the blast at considerable ranges, but this performance falls short if the weapon is equipped with a noise suppressor. Although such silencers aren’t as effective as they appear to be in the movies, they are still able to trick a microphone. Infrared sensors may be used to detect muzzle flash, but they must be in the direct line of sight of the enemy weapon. And just as with muzzle blast, the flash may be suppressed.
Rifle bullets are generally supersonic, producing the same shock waves as high-speed aircraft. These waves result in small, incredibly fast sonic booms that may be heard at distances of a mile or more. The ability to detect these booms falls away if subsonic ammunition is used. Bullets also create highly turbulent vortices as they slash through the air. These vortices create pressure changes in the air mass that are detectable by laser radars. In addition, infrared sensors can detect the heat, or thermal signature, of the projectile in flight.
“Glint” detectors, such as the SLD 500 from CILAS, a French manufacturer of industrial lasers, are used to spot sniper optics. They shine a laser beam in the enemy sniper’s suspected direction; upon contact with the front lens of his telescopic sight or other optical device, reflected energy, or “backscatter,” is emitted and subject to detection. Such systems allow threats to be pinpointed quickly and identified with a high-resolution digital camera.
Detecting crack and bang
A number of vendors offer acoustic gunfire detection systems, although the size, complexity and power requirements of the current generation restrict their use mainly to fixed installations or vehicles. One example is the Precision Direction and Cueing system from Maryland-based AAI Corp., a company perhaps better known as a builder of tactical unmanned aerial vehicles for the Army.
One PDCue product is built around a tetrahedral acoustical array mounted on the left or right rear corner of a Humvee. Microphones listen for the bullet’s “crack,” or shock wave, and the “bang,” or muzzle blast. If the crack is detected, the system computes the bearing to the sniper’s location and its elevation. If the bang is detected, the range to the target may be computed.
An LED display provides the main operator interface, although a Microsoft Windows-type graphical user interface that can display the track of the vehicle and all shots relative to its current position is available as an option.
With PDCue, instantaneous data are provided at speeds of up to 60 mph. The system may be linked to a remotely fired machine gun, which is programmed to pivot and fire once the operator confirms the sniper’s suspected location. Weapon slewing occurs automatically with a touch of the screen.
“The biggest limitation with remote weapons is the slew rate, which is around 90 degrees per second,” said Chris Yaniger, director of advanced technology programs at AAI. “It’s not always as fast as a human gunner, but it does get him off the roof of the vehicle.”
AAI’s top-of-the-line GDS is a “four-corner” unit that offers the same features as the tetrahedral setup, but with a sensor array mounted on each corner of the Humvee’s roof. Higher-accuracy azimuth solutions are available in crack-only or bang-only scenarios, Yaniger said. The four-corner system is also said to be the best fit for the developmental Common Remotely Operated Weapon Station.
BBN, a Boston-based high-tech company that launched the Arpanet, forerunner to today’s Internet, builds the Boomerang, an acoustic detection system that reports sniper azimuth, range and elevation. Like PDCue, it’s a mast-mounted acoustic GDS geared toward Humvee applications.
About 125 of these systems are in theater, according to BBN Vice President Mark Sherman, divided between Army and Marine forces in Iraq and Afghanistan. A further 150 systems are on order, he said.
Work is nearing completion on a third-generation Boomerang that will offer less complexity, lighter weight and reduced installation time. Sherman said this system has virtually eliminated the problem of false alarms, because it will not go off without the presence of a bullet shock wave. BBN is also working on a man-portable/man-wearable GDS, although details regarding this system have not been released.
Rafael, the Israeli armament company, produces the Small Arms Detection System, a conventional acoustic GDS with mast-mounted microphones. It also makes the SpotLite Mk-2, which is representative of electro-optical systems that may be tripod or vehicle mounted.
Built around a forward-looking infrared camera, SpotLite has a laser range finder and pointer, GPS receiver and data-processing unit. The unit may be operated remotely to avoid revealing the positions of countersniper teams employing it.
Viper, a GDS in development with a teaming of the Maryland Advanced Development Laboratory, the Defense Advanced Research Projects Agency and DRS, combines a cooled mid- and long-wave FLIR camera with active and passive acoustic sensors.
This system has been tested in stationary and moving applications, and a prototype was mounted on an Army-leased airship as an emergency measure during the Washington, D.C., “Beltway sniper” attacks of October 2002. Although the unit played no role in that crisis, it nonetheless demonstrated that a GDS could be deployed from an aircraft.
“We’re working on improving processing speed, reducing false alarms and making it cheaper,” said Bud Heidhausen, director of defense programs with the University Research Foundation, part of the MADL. “We’re also building it to be compatible with other types of [GDS], because nobody does a system that does it all. Multi-sensor integration is the key.”
Bullets: more and bigger
As promising as this new technology may be, it is widely believed that the best way to defeat a sniper is with another sniper. This bodes well for the U.S., which enjoys a vibrant precision marksmanship subculture with representation across all five service branches and myriad government agencies.
In line units of the Army and Marine Corps, sniper school graduates generally operate in two-man teams — a spotter equipped with a high-power telescope and defensive weapons, and a shooter armed with a scope-mounted rifle, typically of .308 caliber.
Trained to work while encumbered in “ghillie suit” camouflage, their primary mission involves low-crawling through foliage at a snail’s pace to take a precision shot at a high-value target up to 1,000 meters away. They then creep away, preferably undetected.
This breed of sniper still relies mainly on weapons that require a manual bolt to be cycled after each round is fired, the idea being that these are more accurate than semi-automatic rifles and a follow-up shot would serve only to reveal the sniper team’s position.
In this arena of conventional sniper operations, the biggest change in recent years has been an increase in rifle caliber as a means of extending reach. The .308 is still in widest use, although some special operations snipers have switched to big-game rounds such as the .300 Winchester Magnum. The bullets are the same approximate diameter, but the magnum cartridge is considerably longer and contains a weightier gunpowder charge.
“The .300 round flies flatter, faster and farther than the .308,” said Capt. Marc Messerschmitt, who recently finished a tour as commander of the Army sniper school at Fort Benning, Ga. “Sniper teams using the .300s have a distinct advantage at the longer ranges.”
In terms of big bullets, the ubiquitous Browning .50 caliber, now in its ninth decade of production, has few equals. Sniper rifles built to fire this half-inch diameter cartridge appeared in the 1980s and enjoy a certain cachet among elite forces despite their prodigious size, weight and firing signature.
Line units will soon integrate the .50s, as well. Plans are to procure the Barrett XM107 Long Range Sniper Rifle, a semi-automatic weapon able to penetrate light armored vehicles up to 1,600 meters away, for Army units in significant numbers.
Much of this is academic in Third World cities and towns, however, where buildings and other obstructions serve to restrict engagement distances. In this environment, the best rifle isn’t always the most powerful one, and the ability to fire rapid but accurate follow-up shots — tough with a bolt-action weapon — can make a difference. This has led to the resurgence of gas or recoil-operated sniper weapons based on assault rifles. Army units are slated to receive the Knight Armament Corp. XM110 Semi Automatic Sniper System, a .308 of the same basic Eugene Stoner design as the .223-caliber M16/M4 family of weapons. This rifle will augment, but not replace, the standard-issue bolt-action Remington M24.
Modernized versions of the 1957-vintage Springfield Armory M14/M21 resurfaced in Special Forces units during open desert fighting of the 1991 Persian Gulf War, and Navy SEALs recently introduced a fiberglass-stocked version known as the M25.
For optics, Army snipers rely mainly on Leupold variable-power day sights, while Marines favor a Unertl unit of similar capability. Both services use the Northrop Grumman AN/PVS-10 Sniper Night Sight and the Raytheon/DRS/BAE Systems AN/PAS-13 Thermal Sight. A Defense Department contract to develop a digitally fused weapon sight that would combine real and synthetic imagery is up for bid.
Ellie
Defeating enemy snipers hinges on sensor technology and marksmanship
By Paul Richfield - Staff writer
Posted : March 05, 2007
Well-aimed rifle shots from enemy sharpshooters are second only to roadside bombs when it comes to inflicting casualties on coalition forces in Iraq. Not only have these sniper-style attacks become more frequent and brazen, the insurgents also have taken to videotaping them for propaganda value.
These videos, which are easily accessed on the Internet, reveal the brutal reality of contemporary guerrilla warfare. The victims are typically U.S. soldiers or Marines in the midst of routine duties, seemingly oblivious to the danger they face. Several videos show the shooting of troops standing in the rooftop hatches of Humvees or manning checkpoints. One depicts the killing of a soldier walking on a highway, with the unarmed medic who rushes to his aid shot, as well.
“These attacks do damage, but their greater impact is the ability to spread the terrorist message to a global audience,” said Mark Spicer, a retired British army sergeant major and longtime sniper instructor. “With the videos, the insurgency gets a fantastic return for a very small investment of men and material.”
In many cases, the perpetrators of these acts can not be considered snipers in the traditional sense, because they strike from relatively short ranges with common assault rifles, such as the Russian Kalashnikov AK47. Intelligence officers say they believe the most popular weapon among insurgent snipers in Iraq may be the “Tabuk,” an Iraqi-produced AK47 clone furnished with a lengthened barrel and a low-power telescopic sight.
The insurgency has also employed several versions of the SVD Dragunov, a semi-automatic sniper rifle built in large quantities by the former Soviet Union and its client states, as well as Iraq under Saddam Hussein.
Needless to say, eliminating enemy snipers is a top priority among coalition forces in Iraq. The Army and Marine Corps, for example, are ramping up their sniper and long-range marksman training programs to speed the flow of trained personnel to the war zone without a reduction in quality. And technology designed to reveal the locations of enemy snipers, long in development, is beginning to appear in the field.
Such countermeasures work by detecting the firing of a shot, with the goal of estimating the bullet’s trajectory and tracing it to the sniper’s location. Once the sniper’s location is revealed, it may be subject to countersniper fire, mortar attack or even an airstrike with precision-guided weapons. These firing-related phenomena include the sniper rifle’s muzzle blast and flash; the shock wave, vortex and thermal signature generated by the bullet in flight; and the reflection of light off a telescopic sight or other optical device.
Muzzle blast and flash occur as the bullet leaves the rifle barrel. Acoustic sensors can detect the blast at considerable ranges, but this performance falls short if the weapon is equipped with a noise suppressor. Although such silencers aren’t as effective as they appear to be in the movies, they are still able to trick a microphone. Infrared sensors may be used to detect muzzle flash, but they must be in the direct line of sight of the enemy weapon. And just as with muzzle blast, the flash may be suppressed.
Rifle bullets are generally supersonic, producing the same shock waves as high-speed aircraft. These waves result in small, incredibly fast sonic booms that may be heard at distances of a mile or more. The ability to detect these booms falls away if subsonic ammunition is used. Bullets also create highly turbulent vortices as they slash through the air. These vortices create pressure changes in the air mass that are detectable by laser radars. In addition, infrared sensors can detect the heat, or thermal signature, of the projectile in flight.
“Glint” detectors, such as the SLD 500 from CILAS, a French manufacturer of industrial lasers, are used to spot sniper optics. They shine a laser beam in the enemy sniper’s suspected direction; upon contact with the front lens of his telescopic sight or other optical device, reflected energy, or “backscatter,” is emitted and subject to detection. Such systems allow threats to be pinpointed quickly and identified with a high-resolution digital camera.
Detecting crack and bang
A number of vendors offer acoustic gunfire detection systems, although the size, complexity and power requirements of the current generation restrict their use mainly to fixed installations or vehicles. One example is the Precision Direction and Cueing system from Maryland-based AAI Corp., a company perhaps better known as a builder of tactical unmanned aerial vehicles for the Army.
One PDCue product is built around a tetrahedral acoustical array mounted on the left or right rear corner of a Humvee. Microphones listen for the bullet’s “crack,” or shock wave, and the “bang,” or muzzle blast. If the crack is detected, the system computes the bearing to the sniper’s location and its elevation. If the bang is detected, the range to the target may be computed.
An LED display provides the main operator interface, although a Microsoft Windows-type graphical user interface that can display the track of the vehicle and all shots relative to its current position is available as an option.
With PDCue, instantaneous data are provided at speeds of up to 60 mph. The system may be linked to a remotely fired machine gun, which is programmed to pivot and fire once the operator confirms the sniper’s suspected location. Weapon slewing occurs automatically with a touch of the screen.
“The biggest limitation with remote weapons is the slew rate, which is around 90 degrees per second,” said Chris Yaniger, director of advanced technology programs at AAI. “It’s not always as fast as a human gunner, but it does get him off the roof of the vehicle.”
AAI’s top-of-the-line GDS is a “four-corner” unit that offers the same features as the tetrahedral setup, but with a sensor array mounted on each corner of the Humvee’s roof. Higher-accuracy azimuth solutions are available in crack-only or bang-only scenarios, Yaniger said. The four-corner system is also said to be the best fit for the developmental Common Remotely Operated Weapon Station.
BBN, a Boston-based high-tech company that launched the Arpanet, forerunner to today’s Internet, builds the Boomerang, an acoustic detection system that reports sniper azimuth, range and elevation. Like PDCue, it’s a mast-mounted acoustic GDS geared toward Humvee applications.
About 125 of these systems are in theater, according to BBN Vice President Mark Sherman, divided between Army and Marine forces in Iraq and Afghanistan. A further 150 systems are on order, he said.
Work is nearing completion on a third-generation Boomerang that will offer less complexity, lighter weight and reduced installation time. Sherman said this system has virtually eliminated the problem of false alarms, because it will not go off without the presence of a bullet shock wave. BBN is also working on a man-portable/man-wearable GDS, although details regarding this system have not been released.
Rafael, the Israeli armament company, produces the Small Arms Detection System, a conventional acoustic GDS with mast-mounted microphones. It also makes the SpotLite Mk-2, which is representative of electro-optical systems that may be tripod or vehicle mounted.
Built around a forward-looking infrared camera, SpotLite has a laser range finder and pointer, GPS receiver and data-processing unit. The unit may be operated remotely to avoid revealing the positions of countersniper teams employing it.
Viper, a GDS in development with a teaming of the Maryland Advanced Development Laboratory, the Defense Advanced Research Projects Agency and DRS, combines a cooled mid- and long-wave FLIR camera with active and passive acoustic sensors.
This system has been tested in stationary and moving applications, and a prototype was mounted on an Army-leased airship as an emergency measure during the Washington, D.C., “Beltway sniper” attacks of October 2002. Although the unit played no role in that crisis, it nonetheless demonstrated that a GDS could be deployed from an aircraft.
“We’re working on improving processing speed, reducing false alarms and making it cheaper,” said Bud Heidhausen, director of defense programs with the University Research Foundation, part of the MADL. “We’re also building it to be compatible with other types of [GDS], because nobody does a system that does it all. Multi-sensor integration is the key.”
Bullets: more and bigger
As promising as this new technology may be, it is widely believed that the best way to defeat a sniper is with another sniper. This bodes well for the U.S., which enjoys a vibrant precision marksmanship subculture with representation across all five service branches and myriad government agencies.
In line units of the Army and Marine Corps, sniper school graduates generally operate in two-man teams — a spotter equipped with a high-power telescope and defensive weapons, and a shooter armed with a scope-mounted rifle, typically of .308 caliber.
Trained to work while encumbered in “ghillie suit” camouflage, their primary mission involves low-crawling through foliage at a snail’s pace to take a precision shot at a high-value target up to 1,000 meters away. They then creep away, preferably undetected.
This breed of sniper still relies mainly on weapons that require a manual bolt to be cycled after each round is fired, the idea being that these are more accurate than semi-automatic rifles and a follow-up shot would serve only to reveal the sniper team’s position.
In this arena of conventional sniper operations, the biggest change in recent years has been an increase in rifle caliber as a means of extending reach. The .308 is still in widest use, although some special operations snipers have switched to big-game rounds such as the .300 Winchester Magnum. The bullets are the same approximate diameter, but the magnum cartridge is considerably longer and contains a weightier gunpowder charge.
“The .300 round flies flatter, faster and farther than the .308,” said Capt. Marc Messerschmitt, who recently finished a tour as commander of the Army sniper school at Fort Benning, Ga. “Sniper teams using the .300s have a distinct advantage at the longer ranges.”
In terms of big bullets, the ubiquitous Browning .50 caliber, now in its ninth decade of production, has few equals. Sniper rifles built to fire this half-inch diameter cartridge appeared in the 1980s and enjoy a certain cachet among elite forces despite their prodigious size, weight and firing signature.
Line units will soon integrate the .50s, as well. Plans are to procure the Barrett XM107 Long Range Sniper Rifle, a semi-automatic weapon able to penetrate light armored vehicles up to 1,600 meters away, for Army units in significant numbers.
Much of this is academic in Third World cities and towns, however, where buildings and other obstructions serve to restrict engagement distances. In this environment, the best rifle isn’t always the most powerful one, and the ability to fire rapid but accurate follow-up shots — tough with a bolt-action weapon — can make a difference. This has led to the resurgence of gas or recoil-operated sniper weapons based on assault rifles. Army units are slated to receive the Knight Armament Corp. XM110 Semi Automatic Sniper System, a .308 of the same basic Eugene Stoner design as the .223-caliber M16/M4 family of weapons. This rifle will augment, but not replace, the standard-issue bolt-action Remington M24.
Modernized versions of the 1957-vintage Springfield Armory M14/M21 resurfaced in Special Forces units during open desert fighting of the 1991 Persian Gulf War, and Navy SEALs recently introduced a fiberglass-stocked version known as the M25.
For optics, Army snipers rely mainly on Leupold variable-power day sights, while Marines favor a Unertl unit of similar capability. Both services use the Northrop Grumman AN/PVS-10 Sniper Night Sight and the Raytheon/DRS/BAE Systems AN/PAS-13 Thermal Sight. A Defense Department contract to develop a digitally fused weapon sight that would combine real and synthetic imagery is up for bid.
Ellie