Battlefield Sensors Continue To Make Technological Leaps

Over the past dozen years, the U.S. military has rapidly fielded next-generation battlefield sensors to find roadside bombs and the insurgents who plant them.

Hyperspectral and wide-area surveillance sensors are two examples of technologies that military leaders have touted as success stories. 

But the military can’t stand pat, one government researcher said.

“The last 10 years we have been concentrating on [intelligence, reconnaissance and surveillance] in environments where people can freely say, ‘We are swimming in sensors and drowning in data,’” said Stefanie Tompkins, deputy director of the strategic technology office at the Defense Advanced Research Projects Agency.

But the permissive environment, where unmanned aerial vehicles carrying such sensors fly over warzones unmolested, may not be the situation in which the military finds itself in the future.
DARPA is thinking about new ways to gather data in access-denied areas, she said.

Operating in contested environments means either employing sensors from stand-off distances, or somehow secretly placing them inside enemy territory, she said.

The ultimate challenge would be something buried underground, with a lake over it, a jungle to the side “and maybe a bunch of people trying to shoot at you as well,” she said recently at the Defense Security and Sensing Conference in Baltimore.

In the future, peer adversaries will be doing everything possible to prevent the military from experiencing that “drowning in data” situation, she said. Meanwhile, in permissive areas of operation, there are challenges remaining, she stressed. Finding a specific person in a crowd, for example, hasn’t become any easier, she said.

“At the same time, we are moving into an environment of incredible cost constraints, so we have to try to do the most with less,” she added.

One example is the time and funding the Navy spends hunting for submarines.

DARPA has looked at placing small, inexpensive sensors at the bottom of the ocean in optimal spots to turn them into “underwater satellites.” Instead of a top-down approach to submarine hunting, the looking up tactic has been receiving some positive results in experiments, she said.

These are a “couple of orders of magnitude cheaper than anything we have looked at before,” she said. Using submarines to hunt submarines is expensive, she noted.

“I don’t think the cost constraints are going to go away anytime soon, so I think we should embrace it and really redirect ourselves to a whole new set of really exciting questions,” Tompkins said.

Vendors at the conference, many of them small businesses or research labs, showed that there are still plenty of new ideas and products that can improve the military’s ability to gather data that leads to better battlefield situational awareness.

Advanced Reconnaissance Corp. of Fishkill, N.Y., is working on refining hyperspectral sensors, which became important over the previous decade during the fight to defeat improvised explosive devices. They perceive shades of colors that can’t be discerned by human eyes. They have been used to look for disturbed earth where insurgents may have buried roadside bombs.

“The fundamental technology is hyperspectral, but we have developed some technologies within that sphere that are absolutely unique,” said Mark Westfield, the company’s president and CEO.

The first innovation permits automatic, on-board processing of the data to tell users what they are seeing.

“The Holy Grail is automatic target recognition, and we have achieved that. We tell you exactly what it is,” he said.

The “drowning in data” problem is caused by a lack of human analysts who must wade through hours of video to find what they are seeking.

The processing of hyperspectral and electro-optical sensors inside the company’s Precision ARTIS system provides operators with an image and an annotation on what they are seeing. Disturbed earth caused by someone burying a bomb is different than tire tracks. It can discriminate between the two, Westfield said.

“We don’t have analysts in the middle,” he said. The onboard processor is trained to look for specific objects. “Once our system is trained to find a certain thing, it always finds it,” he said.
The Joint Improvised Explosive Device Defeat Organization bought two of the company’s airborne sensors for use in Afghanistan on manned reconnaissance aircraft. They have one-quarter meter per-pixel resolution at 11,000 feet.

The company was able to strip some of the features needed for the airborne sensor and mount a smaller version on a vehicle that can scan ahead for disturbed earth.

JIEDDO is also interested in a version for dismounted soldiers, Westfield said.

It also has agricultural applications. It can fly over a field and spot unhealthy crops or find an illegal marijuana patch hidden among corn, he added. 

Another company using the color spectrum is Solid State Scientific Corp. of Nashua, N.H. Its 16-color multi-spectral imager is being marketed as something than can quickly defeat camouflage. It is tuned to detect chlorophyll, which is found in every plant, said company representative James Murguia. The processor tags everything green in a scene that doesn’t have chlorophyll in it. Camouflaged items pop out on a view screen.

The Air Force will test it and put it on an unmanned aerial vehicle within the next year, he said.
Another problem that has plagued soldiers first in Iraq and now Afghanistan is brownouts when landing helicopters. The downwash kicks up dust and sand, which makes for hazardous conditions.

Phase Sensitive Innovations, of Newark, Del., is using passive millimeter wave imaging to give pilots a view of what is behind dust clouds. The Coast Guard could also use it for port security during foggy conditions, said Dan Mackrides, a research engineer at the company, which was spun off from a University of Delaware program.

Passive millimeter wave technology uses background radiation to form its images. It has been employed by the Transportation Security Administration to scan underneath passengers’ clothing for weapons or bombs.

In this case, the imager takes radiation emitted from people, other living objects and the ground and contrasts it with the cold sky, which reflects off materials differently.

“If there are any people in the clouds, they are like light bulbs with millimeter wave,” he said.
The sensor uses a distributed antenna array in order to minimize size, weight and power demands on helicopters.

The research-and-development funding came from the Office of Naval Research, and the company is looking for industry partners to take the technology to the next level, Mackrides said.

There are still improvements to be made in two battlefield sensors that have been around for decades: radar and night vision.

As far as radar, work continues on giving operators 3D images instead of flat 2D pictures, said Thomas Goyette, an imaging scientist at the University of Massachusetts. The school’s laboratory is doing work to help the military add this capability.

“Adding the third dimension to it makes it look more like what you are looking at optically,” he said. A front, side and top view help an operator gain a better idea of what he is seeing.
“Let’s just say [the services] have always been interested in 3D imaging, however, it’s been done with varying degrees of success,” he said.

As for night vision, one long-time goal has been to accomplish this without the long image intensifier tubes that stick out from the eye.

One research institute believes it is growing closer to a solid state device that will be flat against the eye like a pair of glasses or goggles. SRI International’s division in Princeton, N.J., has been working on the problem for 10 years, and is preparing to introduce a product at this year’s Association for the United States Army annual symposium in Washington, D.C., in October.

The new imager uses complementary metal oxide semiconductors — more commonly known as C-MOS. These chips are known for low power consumption and smaller size. The new C-MOS system is not quite as good as the night-vision goggles currently being used. Thomas Vogelsong, senior business development director of imaging systems, said the military is never interested in taking a step backwards in terms of performance.

However, the new night-vision sensor could be used in some applications, he said.

“I think there are areas where it will be useful right away,” Vogelsong said. One example would be unmanned aerial vehicles. “They don’t need the high performance of a foot soldier 50 feet away,” he added.

The important development is that military customers now see the possibilities, Vogelsong said. The technology has improved enough over the past few years that they have changed their thinking from “if” there will be a solid-state night-vision goggle that doesn’t use tubes to “when” it will finally come to fruition. 

After October, SRI wants to put the new sensors in the hands of customers who can go out and do field testing and try it for different applications, he said.

Topics: C4ISR, Sensors, Science and Engineering Technology