Active camouflage

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Illustrating the concept, i.e. active capture and re-display, creates an "illusory transparency", also known as "computer mediated reality"

Active camouflage or adaptive camouflage, is a group of camouflage technologies which allow an object to blend into its surroundings by use of panels or coatings capable of altering their appearance, color, luminance and reflective properties. Active camouflage has the potential to achieve perfect concealment from visual detection.

Active camouflage differs from conventional means of concealment in two important ways. First, it makes the object appear not merely similar to its surroundings, but invisible through the use of perfect mimicry. Second, active camouflage changes the appearance of the object in real time. Ideally, active camouflage mimics nearby objects as well as objects as distant as the horizon. The effect should be similar to looking through a pane of glass, making the camouflaged object practically invisible.

Active camouflage has its origins in the diffused lighting camouflage first tested on Canadian Navy corvettes during World War II, and later in the armed forces of the United Kingdom and the United States of America.

Current systems began with a United States Air Force program which placed low-intensity blue lights on aircraft. As night skies are not pitch black, a 100 percent black-colored aircraft might be rendered visible. By emitting a small amount of blue light, the aircraft blends more effectively into the night sky.

Active camouflage is rumored to have taken a new turn with the development of the Boeing Bird of Prey, which apparently took the technology further. The Bird of Prey was a black project and details about it are sketchy.

Active camouflage is poised to develop at a rapid pace with the development of organic light-emitting diodes (OLEDs) and other technologies which allow for images to be projected onto irregularly-shaped surfaces. With the addition of a camera, an object may not be made completely invisible, but may in theory mimic enough of its surrounding background to avoid detection by the human eye as well as optical sensors. As motion may still be noticeable, an object might not be rendered undetectable under this circumstance but potentially more difficult to hit. This has been demonstrated with videos of "wearable" displays where the camera could see "through" the wearer.

1 Active camouflage or "scramble suit"
2 In other animals
3 Optical Camouflage
4 See also
5 References
6 External links

[edit] Active camouflage or "scramble suit"

Wearable and not very convincing version of illusory transparency made from a tiling of flat panel displays supplied with images from cameras, and a computer processing system. This functioning prototype is limited by the number of sensors and transducers.

The active camouflage suit by name is credited to science fiction author Philip K. Dick in his 1974 novel A Scanner Darkly. Worn by the narcotics double agent Bob Arctor/Fred, the "scramble suit" is described as a flexible sheath covering the body of the wearer with a reflective/refractive coating on the inside surface that transfers the camouflaging pattern—projected by a holographic lens mounted on the wearer's head—onto the outside surface of the sheath.

Dick's invention has been copied many times in novels, films and video games to become a standard device in science fiction. Examples appear in the Arnold Schwarzenegger film Predator, the James Bond film Die Another Day, the Metal Gear Solid video game series, the Halo video game series, and the Japanese anime and manga Ghost in the Shell—cited as the inspiration for Tokyo University experiments into optical camouflage. A similar cloaking device is found in Star Trek, however this example does not achieve active camouflage in the same way.

It is notable that in "Ghost in the Shell", the thermoptic camouflage offers concealment in both the optical and infra-red electromagnetic frequencies.

Also in the book series Artemis Fowl the L.E.P (Lower Elements Police) have technology similar to this in the form of "camfoil". While invisible to human eye, it does not work with cameras and can be shorted out by a shower.

[edit] In other animals

Active camouflage is not a human invention. The most convincing example of active camouflage in animals is the octopus, which can blend into its surroundings by changing skin color as well as skin shape and texture. It is a common misconception that the chameleon can change its color to blend with its surroundings. Rather, the color changes occur based on body temperature and how stressed the chameleon is. The ability is also used to communicate with other chameleons.

A fictional example of active camouflage in animals is the Gila-Munga, a race of extraterrestrial assassins appearing in Judge Dredd, a story serialized in the weekly British comic book anthology 2000 AD.

[edit] Optical Camouflage

Optical camouflage is a kind of active camouflage which completely envelopes the wearer. It displays an image of the scene on the side opposite the viewer on it, so that the viewer can "see through" the wearer, rendering the wearer invisible. The idea appears in many fictional works, such as the William Gibson novel Neuromancer, where it is referred to as a "mimetic polycarbon suit," and the 1979 novel "Mirror Friend, Mirror Foe" by George Takei and Robert Asprin. Also referred to as "thermoptic camouflage" or simply "thermoptics," this technology was popularized by the sci-fi manga (and later anime) Ghost in the Shell. It has also been featured in the 2000 game Deus Ex, the 2002 James Bond movie Die Another Day, as well as a similar technology appearing in the Metal Gear Solid video game series, the Halo video game series, Tom Clancy's Splinter Cell: Chaos Theory, the video game Phantom Crash, In The Predator movie franchise (Activated on a gauntlet) and as an unlock for the "scout" class in a Half Life 2 mod, "Empires". An optical camouflage device appears in the PC game Battlefield 2142 as an unlockable item.

Outside of fiction, the concept exists only in theory and in proof-of-concept prototypes, although many experts consider it technically feasible. In 2003, three professors at University of Tokyo — Susumu Tachi, Masahiko Inami and Naoki Kawakami — created a prototypical camouflage system in which a video camera takes a shot of the background and displays it on the cloth using an external projector. The same year Time magazine named it the coolest invention of 2003. [1] With flexible electronics such as a flexible liquid crystal display that would permit display of the background image by the material itself, this form of optical camouflage may closely resemble its fictional counterparts.

Phased array optics (PAO) provides the most perfect implementation of optical camouflage yet proposed. Instead of producing a two dimensional image of background scenery on an object, PAO produces a full color three dimensional hologram of background scenery. Unlike two dimensional images, the holographic image remains indistinguishable from true invisibility independent of object distance or view angle.

[edit] See also

[edit] References

Burr, E. Godfrey. "Illumination for Concealment of Ships at Night." Transactions of the Royal Society of Canada (Third series, volume XLI, May 1947, p. 45-54).
No Day Long Enough: Canadian Science in World War II. Editor: George R. Lindsey. (Toronto: Canadian Institute of Strategic Studies, 1997), p. 172-173.
Summary Technical Report of Division 16, NDRC. Volume 2: Visibility Studies and Some Applications in the Field of Camouflage. (Washington, D.C.: Office of Scientific Research and Development, National Defense Research Committee, 1946), p. 14-16 and 225-241. [Declassified August 2, 1960].
Waddington, C.H. O.R. in World War 2: Operational Research Against the U-Boat. (London: Elek Science, 1973), p. 164-167.