The future infantry soldier, who already is looking at new personal armor and communications systems, also may be equipped with a multisensor system that can provide him with a range of spectral views that can be changed with the flip of a switch. Helmet-mounted sensors would comprise both infrared and image intensifiers, and rifle sights would provide multispectral capability. Information gleaned from these sensors would fuel network-centric operations.
These advances would not be limited to the muddy boots professional, however. U.S. Army aviators would enjoy better vision and force identification to enable them to shoot first with little fear of fratricide. Nonhuman participants, such as unmanned aerial vehicles (UAVs) and robotic ground platforms, also would see benefits from improved sensors that open up new capabilities. Ultimately, the future battlespace would be dominated by sensors out front on small robotic platforms. Non-line-of-sight weapons would affect a considerable amount of combat.
Much of the Army’s research into these new tactical sensor technologies is being performed by its Night Vision and Electronic Sensors Directorate (NVESD) of the Communications-Electronics Research and Development Center at Fort Belvoir, Virginia. Its director, Dr. A. Fenner Milton, explains that signal processing power, photolithography and materials technology all are emerging as key to successful sensor development.
Research and development at the NVESD concentrates on three technologies: image intensifiers, infrared thermal imagers and laser rangefinders and designators. Image intensifier technology, which was the original night-vision enabler, has progressed several generations beyond its image tube origins. These technologies now are equipping goggles and rifle sights with improved low-light-level performance and resolution.
Milton points out that these technologies are still maturing. Right now, the laboratory is making much smaller cameras with reduced weight and power consumption. In addition to lightening physical demands on the individual soldier, future digital image intensifiers may be able to provide indirect-view imagery.
Infrared thermal imagers, which equip forward-looking infrared (FLIR) systems, currently are used on major platforms. In the past few years, second-generation thermal imaging technology has emerged to provide improved capabilities. Now, infrared imaging research is focusing on development of a new capability that would be multispectral. However, significant material challenges to reaching this goal loom. Using mercury-cadmium telluride materials to achieve this capability poses a problem. The laboratory has “substantial produceability programs” tasked with solving the difficulties of producing these materials at a reasonable cost.
One focus is to try to grow mercury-cadmium telluride on a silicon substrate. Milton describes the laboratory’s effort as “a program that we have a lot of hope for, but clearly we cannot guarantee [success] at this point.”
The laboratory is moving from fabrication using liquid phase epitaxy to molecular beam epitaxy, he continues. This technology, combined with the successful goal of using a silicon substrate, would produce the needed capabilities at a reasonable cost.
For less expensive systems, the laboratory is working on uncooled focal plane array technologies, focusing on microstructures and vanadium oxide materials. This technology has advanced rapidly over the past few years, Milton notes, and scientists now can build thermal imagers that do not need cryocoolers. By eliminating these complex, weighty and expensive devices, infrared focal plane arrays can be built to be much smaller and lighter, use less power and cost much less.
The individual soldier may finally have “infrared on the head,” Milton says. These new infrared sensors will have a greatly improved target-clutter contrast over the detection capabilities of image intensifiers. This in turn will provide a significant improvement in night viewing for dismounted infantrymen. Users will be able to find targets more quickly and avoid ambush, as well as operate in a close environment where there is no ambient light for image intensifiers. Smaller UAVs also will be able to reap this technology benefit, and missiles could be equipped with uncooled seekers.
Laser rangefinders and designators, which are the third major NVESD technology, are used extensively to locate targets accurately and to direct laser-guided weapons. Much of the laboratory work involves producing lasers that are smaller and lighter so they can be used by individual soldiers and small UAVs.
Considerable laser imaging work has focused on eyesafe wavelengths. Applications would be narrow-field-of-view, long-range identification systems. Milton says that this work has come along well with substantial advances. The result is hitherto unavailable image tubes that work at the eyesafe wavelength of 1.5 microns.
NVESD scientists have been pursuing some new avenues of research in laser development. One approach led to a simplified laser system pumped by an unusual commercial off-the-shelf technology. But it was the development of this small laser’s flashlamp that broke the mold of conventional laser construction. Commercial disposable camera flashlamps have proved both effective and reliable, as NVESD officials report that one of them has fired its laser more than 10,000 times. Similar flashlamps are being used in the Cobra and Storm laser rangefinders that have been used in Afghanistan and are heading to Iraq.
A program built around this technology developed a multifunction laser sensor that can serve as a rangefinder, near-infrared aim light, visible aim light, near-infrared illuminator and digital compass. Incorporated into the Cobra, the system is mounted on the M-4 and the M-119. This unit, based on the prototype, weighs 1.6 pounds, and a new version will weigh only 1 pound.
Advances in these three sensor categories may change the way the Objective Force Warrior views the battlespace. Because the imaging systems operate in vastly different wavelengths, they will require separate sensors. However, especially with the new image intensifiers allowing indirect viewing, these separate sensors could be linked into a single display system.
This same capability could be extended to unmanned vehicles, and Milton reports that researchers are looking to use robotic platforms to move these sensor systems in the forefront of the battle. Milton allows that the Army has increased its emphasis on sensors for robotic platforms. This would help avoid crew vulnerabilities in dangerous missions. For sensor researchers, this translates to lightweight packaging so that more sensors can fit on a small platform.
The network-centric warfare capability that is driving the ongoing force transformation may be able to receive information from these soldiers’ sensors. Milton emphasizes, however, that no plans exist to move each sensor’s data directly into the network. Current efforts involve moving information—as opposed to raw data—from multiple sensors into the network.
Power remains an important issue in sensor development. Improved sensor capability could be offset by greater power demands, which would increase the weight a soldier would have to carry in batteries.
One area where advances have been a key enabler of these sensor innovations is signal processing. Commercial breakthroughs in signal processing have proved extremely useful, as Army engineers are able to incorporate smaller computing devices into their systems. Milton relates that, in many cases, the Army is adapting technology that has been developed elsewhere. “For once, the Defense Department hasn’t had to pay the full freight,” he adds.
The full version of this article appears in the November 2003 issue of
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