New Technologies Fuel Advancements in Night Vision Goggles

Unlike the massive acquisition programs for fighter jets and combat vehicles, night vision technologies need to be refreshed every few years in order for troops to maintain their edge against adversaries. Scientists have focused on improving image quality while driving down the size, weight and power consumption of these devices.

For the first time, the Army is simultaneously procuring a new suite of night vision goggles and weapon sights that can combine imagery from both devices. The coming years may bring greater advancements. Officials from military research organizations believe that a shift from analog to digital night vision devices will soon be possible, yielding the prospect of capturing and sharing color video among soldiers.

For decades, the U.S. military relied on analog night vision goggles that use image intensification tubes to amplify existing light, allowing troops to see in practically pitch-black conditions.

“The image intensifier is almost a perfect technology. It consumes extremely little power, [and] it’s very light,” said Don Reago, acting director of the communications and electronics research, development and engineering center in the Army’s Night Vision and Electronic Sensors Directorate. The problem is that image intensifiers cannot operate without some source of light.

The Army’s newest goggles incorporate thermal imaging so that soldiers can see even if there is no visible moon, stars or nearby cities to provide ambient light. The enhanced night vision goggles, manufactured by Exelis, overlay image intensified and infrared images.

Now the Army is looking for goggles that seamlessly operate with clip-on, infrared weapon sights. The service in February released a solicitation for the enhanced night vision goggle III and a corresponding family of weapon sights.

Like its predecessor, the new devices will combine thermal imaging and image intensification. However, the ENVG IIIs will also include “rapid target acquisition” technology, which will wirelessly send imagery from the weapon sight to the goggles, allowing the soldier to see both images blended together.

Without rapid target acquisition, a soldier who sees an adversary in his night vision goggle would have to flip the goggle up in order to look through the weapon sight and view the target, said Jeff Miller, Raytheon’s vice president of combat and sensing systems. “Rapid target acquisition actually puts that image from the sight on the rifle into the goggle, so he can leave his goggle down and fire much more quickly.”

Fielding a rapid target acquisition technology could reduce the time it takes for a soldier to detect and engage a target by 50 percent, the solicitation said. That would enable soldiers to be more lethal and effective, while increasing their ability to quickly operate at night.

The sight will be a “weapon-mounted long-wave infrared sensor used for surveillance and fire control of individual weapons during daylight, darkness, adverse weather and dirty battlefield conditions,” the solicitation said.

The government intends on awarding up to two indefinite delivery/indefinite quantity contracts. Exelis and Raytheon are two of the companies gunning for awards, but company officials declined to provide specifics on their offerings. 

Ultimately, what company wins the contracts will be determined by which one can meet requirements at the lowest cost, weight and size and with the least power consumption, Miller said. The Army will likely announce a winner in the first half of 2014, he added. 

Rapid target acquisition was developed by the night vision directorate in concert with industry partners, BAE Systems and DRS Technologies. Work started in 2010, when engineers at the Army’s night vision lab received feedback from soldiers who wanted to view images from their goggles and weapon sights at the same time, Reago said.

“The tricky part, scientifically, is you want the image in the rifle sight to be correctly positioned relative to the imagery in the goggle. So if the rifle sight is looking a little bit to the right, you will see the image a little bit to the right in the ENVG [enhanced night vision goggle],” he said. “We spent a lot of time developing that capability, which is based on software and some sensor technology.”

The directorate will transfer the technology to Program Executive Office Soldier within a year, Reago said. Until then, it is continuing to refine the software and make it more user-friendly.

The most difficult and enduring problem for developers of night vision goggles is how to affordably move from analog to digital technologies while maintaining low size, weight and power consumption. The directorate has been working for about 15 years to develop digital alternatives to image intensifiers, and Reago believes a digital device could be ready for fielding as early as three years down the road.

There are no digital head-mounted night vision goggles in use because technology has not advanced to the point where they are small and light enough to be worn on a helmet, said Eric Garris, network systems strategist and lead engineer for Exelis.

Reago said transforming analog images to digital is also difficult. “If you want to digitally combine image intensifier data with thermal data and give the user a truly fused picture, you have to resort to some complex engineering to get the information digital, and it reduces performance of the image intensifier and adds to the cost,” he explained. 

The directorate formed a digital night vision consortium with industry in 2011 to help pioneer digital image intensification alternatives. Its members are BAE, Jazz Semiconductor, Sarnoff Corp., Teledyne Technologies Inc. and SiOnyx.

Reago would not specify any details about the prototypes being built by the consortium, except that the manufacturers are concentrating on less expensive silicone-based imaging technologies.

Prototypes are expected by the end of the year for testing in 2014 at the Maneuver Center of Excellence at Fort Benning, Ga. The goal is to manufacture a camera that weighs under a pound and is an inch wide, he said.

There are two ways to create a digital replacement for image intensifiers, he continued. Either they can make a camera sensitive enough to amplify very small amounts of light, or they can use a camera with extremely low-noise sensors.

Moving to digital would generate a host of new capabilities. Unlike analog, digital video can be recorded and transmitted over a network, either to a command post or soldier-to-soldier. It could also be fused together pixel-by-pixel with thermal imaging, as opposed to the overlay of thermal and optical imaging currently used in enhanced night vision goggles, Reago said.

Color images and video are also a possibility with digital night vision technologies. This would allow troops to see if a comrade is wounded or to quickly read and process signs in urban areas, he said. 

The directorate is experimenting with filters that help sensors retain the ability to transmit color, even in low light. The technology is still imperfect — in order to convey more color information, the resolution of the image is degraded, Reago said.

Other military organizations are also pursuing digital technologies for the individual soldier. The Defense Advanced Research Projects Agency is working on a digital helmet-mounted multiband camera and clip-on weapon sight that can see day and night in any weather conditions.

The camera and weapon sight would fuse reflective light in the visible, near infrared, short-wave part of the spectrum, as well as thermal images from the mid-wave and long-wave portions into a single image, said Nibir Dhar, who manages the program for DARPA. Making the devices as small as possible is another objective of the program, called Pixel Network for Dynamic Visualization, or PIXNET.

The research agency in July awarded $8.6 million to Raytheon and $8.9 million to Sensors Unlimited Inc. to develop a helmet-mounted camera. DRS Technologies’ reconnaissance, surveillance and target acquisition division picked up a $15.5 million contract for the weapon sight.

Both devices will be wirelessly connected to an Android smartphone. Although peer-to-peer sharing is not a requirement of the program, soldiers would be able to use the smartphone to send images over a network. “For example, a team leader could look at it and make some sort of app” or could send the image for forensic processing, Dhar said.

The target cost-per-unit for the helmet-mounted camera is $3,300. A target cost of the weapon sight has not yet been defined, but will likely be more expensive because it has to be able to see at longer distances, he said.

The PIXNET program kicked off in August after manufacturers were selected and met with DARPA officials to compare notes, Dhar said. Testing of prototypes is planned for 2015 with final delivery in 2017.

Small thermal cameras for the dismounted soldier are also receiving research-and-development dollars at both the Army’s night vision directorate and DARPA.

Engineers at the directorate are engaged in efforts to decrease pixel size from 17 to 12 microns, Reago said. It typically takes only three to five years for the research-and-development community to introduce such a reduction.

“As the pixel size gets smaller, it allows us to make the sensors much smaller and it allows us to increase the resolution without making the sensor larger,” he said. “Imagine going from something that’s 2 or 3 pounds and the size of half of a shoe box … to something that is less than a pound and the size of a small water bottle.”

DARPA’s “low cost thermal imager” program is aimed at refining manufacturing for infrared sensors to make them small enough to embed in smartphones, rifle sights or eyeglasses and affordable enough to purchase for every soldier.

Like the Army’s night vision directorate, DARPA and its industry partners were able to shrink pixel size to 12 and 10 microns. They also developed new optical materials that can be stamped on a wafer in the same way cell phone cameras are manufactured, Dhar said.

DRS, BAE and Raytheon will demonstrate their smartphone-embedded thermal cameras in November, he said. After that, companies will finalize, manufacture and deliver their designs to the Army for field testing in 2015.

Ultimately, it’s possible that small thermal cameras will become more common in the commercial sector if industry decides to spin off these technologies to products geared toward the public, Dhar said.

“When you start to make [thermal] cameras [for] $500 or less — that’s the goal — it opens doors for a variety of commercial applications,” he said. “You will have these cameras on your smartphone, on your vehicle to drive at night, for security, and so on.”

Photo Credit: DARPA

Topics: Science and Engineering Technology, DARPA