/ / / / GCT 2013 Volume 4 Issue 3 (August)

Night Vision Systems

The enemy is on the move, day and night, so the U.S. Army’s Night Vision and Electronic Sensors Directorate (NVESD) specifically develops technologies to enhance soldiers’ situational awareness. Night vision systems (NVS) provide a tactical edge, but their accuracy in identifying threats is critical, according to NVESD Ground Combat Systems Director Tom Bowman. “Our soldiers fight in very restrictive rules of engagement (ROE), where targets must be positively identified as enemy combatants before a weapon is fired,” Bowman said. “This is further complicated when threats mix in with non-combatants.”

To give our warfighters a confidence boost in separating threats from non-combatants, NVESD is working on sensors that will augment existing technologies. The sensors will use “nontraditional” wavelengths, taking advantage of optical physics that still enables covertness while providing high resolution images. The directorate is also working on novel optical designs that reduce sensor weight by 50 percent. Those designs are being incorporated into new thermal weapon sights (TWS).

One additional innovation is NVESD’s development of rapid target acquisition (RTA) technology. “RTA is a paradigm shift for individual thermal weapon sights by allowing the soldier to use a sensor offensively by giving the individual soldier the capability to ‘shoot from the hip’ by transferring, wirelessly, his weapon pointing and sight imagery up to a head-mounted display,” Bowman said. “We are currently testing these technologies with our user community with much success.”

While there are advantages gained from newer assets, the green color displays of sensor information are still the preferred method in today’s night vision systems, although NVESD does sometimes use black and white displays when fusing imagery with other sensors.

“The human eye has the most sensitivity to wave lengths of light in the 500- to 600-nm region (green color spectrum), so we use green in night vision systems to minimize the amount of brightness needed and maintain the best overall performance,” Bowman said. He predicts that in the future, emerging technologies will enable a transition from night-only devices to day and night devices, resulting in adding color instead of monochrome green. “Color aids the display of map imagery from personnel data assistance, day TV cameras and other developments, easing use for our soldiers,” he said.

The Direction of NVS

The state-of-the-art technology in night vision is the ability to always provide visibility of targets and surroundings during day, twilight and all levels of darkness, according to Meprolight Marketing and Sales Manager Zvika Lisichkin. “The solution to that is fusion between a high-quality thermal infrared [IR] and starlight intensification system that solve most visibility problems,” he said.

Keeping the weight down is a priority for Meprolight as they look for innovative ways to lighten the load of their thermal weapon sights. “We try to make our sights as light as possible because we know the importance of mobility and fast reactions to the soldier,” Lisichkin said. “We always try to find the lightest materials for the body of our TWS and to fit in the smallest microbolometers possible that still provide a high-quality image.”

There’s no question about the requirement for lightweight systems, but a lighter system isn’t the top choice if it can’t perform the task at hand. “For example, thermal can’t see through windows and image intensification can, which give it a tactical advantage in urban fighting,” he said. “Also, you can mark targets using IR non-visible lasers for covert ops and close quarters combat using a helmet-mounted monocular and an IR laser on the rifle for fast shooting from the waist.”

Night vision technology has continued to advance over the past few years, with product solutions based on both image-intensification as well as infrared imaging, according to Michelle Intiso, inside sales manager at Sofradir-EC. “Because of significant military budget restrictions, including the impact of sequestration, and the current level of military activity, new product designers are motivated to meet the required performance requirements at a target cost,” Intiso said. “For example, for portable and mobile products, new designs often seek not only minimum SWaP [small size, low weight and power], but also minimized cost, hence ‘SWaP-C.’”

Uncooled cores are now available for night vision systems based on thermal imaging. These cores deliver improved thermal sensitivity and high resolution at a reasonable cost, Intiso said. “Uncooled systems are commonly found not only in portable night vision solutions such as enhanced night vision goggles and thermal weapons sights, but also in IR security cameras, mobile platforms of UAV surveillance and driver’s vision enhancers,” she explained. “Cooled IR imaging systems continue to deliver the best possible performance in several spectral bands, including LW, MW and SW.”

Sofradir-EC has its sights focused on three key areas: the development of night vision modules designed to amplify low-light to better enable digital SLR cameras and high definition camcorders to acquire nighttime images; the design of uncooled IR cores with state-of-the-art array resolution (1024-by-768) for driver’s vision, distributed aperture and surveillance products; and the introduction of cooled IR imaging engines in LW and MW IR spectral bands for a variety of applications, including fire control, missile warning, ISR and sights.

Sofradir-EC has participated in training exercises that gave them opportunities to speak with ground combat personnel who shared their operational experiences, describing situations in which superior nighttime image capture was required. “This has been extraordinarily valuable to implement designs that better meet the needs in the field,” Intiso said.

That exposure helped them introduce several products over the past year, including: AstroScope night vision modules designed for use with a new family of full-frame digital SLR cameras that eliminate vignetting yet result in very high performance at night; high resolution uncooled IR cameras, like the Atom 1024 with continuous zoom 25-225 mm, delivering 60 percent improved detection range over video graphics array-based systems; and the high performance miniature IR thermal imaging engine LW cooled IR imaging engine for state-of-the-art nighttime detection.

Distribution Perspective

Tucson, Ariz.-based Alternative Vision Corporation (AVC) distributes image sensors and digital cameras to industrial and scientific customers worldwide. The company also provides sales and marketing services to some of their nine vendor lines, giving AVC President David Gilblom a unique perspective on night vision technology, which he currently calls “photon-limited in the visible and cost-limited in the infrared.”

He sees room for incremental progress in the visible, but said that the sensors available now do a pretty good job of capturing and converting available photons and preserving their signals. “In every infrared band, the challenge is getting the cost down both by developing better uncooled sensors and by developing less-expensive production processes,” he said. ”Of course, finding a material that would allow construction of uncooled photon detectors in the infrared would provide a major breakthrough, especially in the mid-wave band, but that is not likely to happen anytime soon.”

One innovation he saw recently came from Lumiense Photonics, which has developed visible image sensors with near 100 percent quantum efficiency and low noise, and long-wavelength infrared (LWIR) sensors that can be built using standard complementary metal-oxide-semiconductor processes. “They incorporate a frame reset functions to eliminate image lag,” he said. “We hope to have these devices on the market before the end of this year.”

Ultimately, these products will be combined in a single device to permit wider deployment of high-performance visible and infrared cameras with substantial size and cost reductions. “Combining the visible and LWIR sensors into a single device eliminates the need for separate optics and image processing to register the visible and infrared images, giving the soldier less to carry while providing better information,” he said.

Somewhere down the line, a soldier may be able to see clearly at night through an enhanced windshield in Army vehicles. “We have just completed a joint research project with our sister Army Research, Development and Engineering Command organization, the Army Tank, Automotive Research, Development and Engineering Center,” Bowman said. “One of the purposes of this research was to demonstrate 360-degree vision to a vehicle operator and the squad riding in the back.”

The goal was to provide all-around situational awareness while the vehicle operated with its hatches closed. “We use the term ‘transparent armor’ to describe the type of information an operator sees while using the system.” NVESD’s part in the process included developing wide field of view day and night sensors with increased resolution. “These sensors enabled the soldiers to operate as if they had no armor to block their view,” Bowman said. “This proved successful for operations in both open, rolling [environments] and complex [urban] environments.”

Eventually, transparent armor will be incorporated into future Army programs such as the ground combat vehicle, but for now, NVESD’s top priorities for the future remain the same as they always have been. “We are constantly looking at developing the right technology that meets warfighters’ future needs,” Bowman said, noting that cost is an important aspect. “We are constantly evaluating the cost of our sensors for ways to reduce manufacturing costs while providing new capabilities.”

For the most part, the technologies NVESD develops are specific to the military and few commercial applications exist. In addition to the directorate’s research to reduce the sensor weights, NVESD is always looking to reduce power and the number of batteries needed. “We rely heavily on the commercial side to reduce size and power of electronics while providing expanded capability,” Bowman said, citing the commercial cell phone market as a great example of smaller size with much increased capability. “Although our technologies have little commercial application, there are areas of overlap and we capitalize on those advancements to reduce our costs while increasing capability.”

These TWS advancements result in success for our ground combat troops. “We work extremely hard to provide our soldiers with the best night vision technology, enabling them to fight and survive on the battlefield,” Bowman said. “Our mission today is to examine additional opportunities that allow soldiers to operate on tomorrow’s battlefield against complex and unique threats while operating in the limited fiscal situation the Army faces: Our aim is to develop the right technology with minimum cost.” ♦

Last modified on Wednesday, 22 January 2014 12:42

Additional Info

  • Issue: 3
  • Volume: 4
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