Posted on 10/01/2002 6:15:17 PM PDT by VaBthang4
Owning Even More Of The Night
Nighttime Color Viewing Is No Longer The Stuff Of Science Fiction
The proliferation of night-vision systems throughout the US military services validates US forces' claims to "owning the night." Innovations abound in the night-viewing field, as evidenced by the increasingly sophisticated systems worn on soldiers' helmets and attached to their weapons, the more specialized devices designed for aviators, and those that go to sea on submarine periscopes.
But in spite of the nighttime vistas that are opened up by night-vision devices, they share a common shortcoming: All are monochromatic. Soldiers, airmen, and submariners can detect movement and discern telltale features of scenes that are viewed with these systems, but it often falls to the observer to interpret the nuances of activities and objects that can now be seen only in shades of green or gray.
US forces have long sought a breakthrough technology that would make it possible to observe nighttime activities in near-real color. Toward that goal, US military officials feel that a realistic schedule for acquiring a nighttime color-viewing capability should put such devices within reach in about seven or eight years. At least that's what the folks in the night-vision business tell them.
As a result, the big push within the night-vision community focuses on sensor fusion-combining the inputs from the two existing technologies (light-intensifying night-vision capabilities and infrared thermal viewers). There's also an internal conflict within military circles over just how useful color would be: The "door-kickers"-those who use devices such as flash-bang grenade-probably would have less need for color-capable devices than would, say, a sniper or helicopter pilot. Those are the major reasons why there is presently no valid US military requirement for a color-capable night-vision device. And we all know how the absence of a valid requirement can sidetrack innovation in the Pentagon's requirements-driven, materiel-development and procurement processes.
Peter Jones, president of the Boston MA-based Tenebraex Corporation, recently ran into the "no requirement" barrier in his attempts to generate interest among US military organizations in a prototype color-capable night-vision device that he developed. Tenebraex's ColorPath(tm) system is designed to clip on existing PVS-14 night-vision goggles (NVGs). That was reason enough to invite Jones to AFJI's annual "Shoot-out" (see feature article), where he had an opportunity to demonstrate his prototype device to members of the US Special Operations and weapons-development communities. And Jones' first public demonstration generated some well-deserved interest.
Following the AFJI-hosted event, Jones was invited to demonstrate the system for officials at the Marine Expeditionary Unit at Camp Lejuene, NC and at the US Army Aviation Research Lab, Fort Rucker, AL. The aviation community is particularly interested in determining if a color-capable night-vision device would reduce pilot fatigue. While the results from those demonstrations aren't known, here's what a few of AFJI's evaluators thought about the ColorPath(tm).
"A huge improvement over what we use today," an evaluator noted. "The colors are a little bit off, but it beats seeing just green."
"Although the colors are not 100 percent true, it is an immense improvement over existing NVG technology," wrote another. "It will take much more testing to say how much better it is than other NVGs for depth perception and eye strain."
"It's very impressive to see something in color in darkness," said another viewer. "It's not true color [e.g., yellow appears white], but it is a definite improvement."
USES ABOUND The primary purpose of night-vision goggles is to give military forces an advantage over adversaries during darkness or inside enclosed spaces with little or no light. Color-capable systems would undoubtedly increase the wearer's advantage over potential adversaries in tactical situations, Jones told AFJI, but he sees many additional advantages in his systems. Attached to night-viewing-capable video cameras, for instance, they would make it possible to identify the color of a suspicious vehicle that repeatedly passes a particular point. They would also be useful in assessing and treating wounds; in reading computer displays; for unmasking camouflage in counter-sniper operations; and for identifying the color of chemical light sources used to mark minefields and landing zones (LZs).
One of our evaluators pointed out that they would probably also make it possible to use standard-issue color smoke grenades at night for marking LZs and for other signaling purposes. Based on that evaluator's comment, Jones has tested the ColorPath's ability to discern the color of orange smoke, which is commonly used in rescue missions at sea. He tells AFJI that the smoke's color was clearly discerniable. When viewed through standard NVGs, the orange smoke looked like fog-"just another shade of green."
The ColorPath(tm) clip-on device gives the user the option of viewing in true color or false color, Jones explained. (He is also developing another system that will actually be built into a PVS-14 and could be modified for any similar NVG. This device will have three modes of operation: normal monochrome [green]; true color; and false color.) Because human eyes can view wavelengths spanning only from about 400nm (blue) to about 700nm (red), NVGs are designed to operate in the blue-green range (about 500nm) out to the near-infrared spectrum (about 900nm). When a viewing device is operating in a "true color" mode, light returns beyond 700nm are excluded, and objects appear as they do when viewed in daylight. In very low light, however, the infrared spectrum must be brought into play, resulting in "false color" returns.
Jones designed the ColorPath(tm) to capture both true color and false color returns so that the user might capitalize on the operational advantages that both modes offer. In addition to the capability of an infrared device to make viewing possible in very low light situations, he said, "the false color mode of the ColorPath(tm) can help a viewer separate returns from camouflaged objects and their natural surroundings. With existing monochromatic NVG systems, a viewer does this principally by looking for sharp edges and other distinguishing characteristics of objects when examining a scene."
These subconscious outline-recognition processes are not required with ColorPath(tm) technology, Jones continued. His device "takes all visible information from the full-color scene, compresses it, and encodes it so it can be carried by the NVG's image-intensifier tube. These data are then presented to the viewer's eye in a manner that prompts the brain to decompress and interpret the return in full color."
Most modern camouflage materials are manufactured to match invisible light in order to defeat monochromatic NVGs. Therefore, "if you can vary the amount of infrared light that you add with false color, I would say that it's impossible to make an artificial material that will match a natural background at every single point," Jones said. "If you can vary the amount of infrared light that you're putting [into an NVG]-varying the false-color effect-you'll be able to find some point where the camouflage doesn't match the background."
Jones is able to demonstrate this by manipulating the flow of infrared light entering an NVG through a filter on the front of the ColorPath(tm) device. In his demo, the US Army's latest battle dress uniform is the object of the nighttime search. The BDU, which is green in true color, matches its background when viewed through a standard NVG. "I can show a mode where the grass turns brown but the camouflage material is still green. That variable false color allows you to find places where the camouflage no longer matches the color of the background.
"But the real breakthrough with this technology is that it works with existing night-vision tubes that use the green P-43 phosphor," Jones continued. "From what I hear, [other approaches to producing color NVGs] require special tubes and, often, multiple tubes. I'm using the green tubes that are already in the system, and we're doing it with one tube. We're using the few tiny spikes of other colors that are already in the P-43 to help encode the color information. What the eye actually sees in the back of our display is mainly green light with a little bit of other colors that we're encoding. The colors that you see are being 'painted in' in your brain. That's why we're so inexpensive."
Having said that, Jones didn't hesitate when asked for an estimate of what the ColorPath will cost. "We're not talking about thousands of dollars; we're talking about hundreds."
Jones has held preliminary discussions with NVG manufacturers in hopes of taking the performance of his prototype clip-on device to the next level, and particularly to continue work on the three-mode, self-contained unit. Considering the cost of such developmental work, he doesn't begrudge the prospect of cooperating with a major NVG manufacturer. "That's reality," he concluded.
Wouldn't make any difference to me - I don't see color right anyway. What would interest me would be better reproduction of shade intensity (dark colors look darker gray/green and light colors lighter shades). (And, prescription eyepieces in my 3rd generation night vision binocs so I don't have to fumble with my glasses to use them at night).
Good point. I'd like an adjustment for that on the control panel - its pretty jarring going from being in the dark to all that light. And, it takes me about 30 minutes to get my night vision back even after just a peek through the binocs. (Maybe put some red gels on the objective lenses?)
Of course I am speaking from a G1 night vision perspective.
I'm speaking from a "Damn, another coyote's trying to get in the chicken yard again - hand me the 30-30" perspective myself ;)
Information about any loss in sensitivity due to going to a color system is precisely what Jones left out of this article. Color vs. threshold sensitivity is a natural consequence of the physics of the sensors involved and that tradeoff can sometimes be quite serious. For example, in the human eye the rods (black & white sensors) are 400 times more sensitive than the cones (color sensors).
I'd be damn sure that I truly needed the color system before I would switch to it. Someone's life may depend on it.
Regards,
Boot Hill
Regards,
Boot Hill
Regards,
Boot Hill
Combine the wider view with the colour display, and they'd really have something.
-archy-/-
I've got a continuing interest in the material designed and produced in the former Soviet Union, all of which is at least a generation behind comprable US-built NVDs, and generally isn't worth the additional hassle and lessened capabilities despite admittedly attractive prices...sometimes, unless your requirements are VERY specific and limited.
But one of the best in the business is: Excalibur Electro Optics. In particular, check out their *helpful info* section for a good overview of the subject and equipment available, and its capabilities.
-archy-/-
do you (or anyone else) know of any good long-eye-relief models that can handle the increased recoil of a magnum handgun (454Casull)? I found one model, a gen3, that was around $2500, and that was with no bells and whistles. I could get by with gen1 sensitivity, but gotta have the eye relief and the shock tolerance.
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