Lightweight optoelectronic systems built around advanced image sensors and display panels have been proposed for making selected objects appear nearly transparent and thus effectively invisible. These systems are denoted "adaptive camouflage" because unlike traditional camouflage, they would generate displays that would change in response to changing scenes and lighting conditions.
The basic overall function of an adaptive camouflage system would be to project, on the near side of an object, the scene from the far side of the object. Although adaptive camouflage was conceived for use in battlefield settings (see figure), there are also potential commercial uses — for example, as an electronic "window" that would display a nearby outdoor scene in an office that lacks a real window, or as a home security system in place of a door peephole.
A typical adaptive camouflage system would likely include a network of flexible electronic flat-panel display units arrayed in the form of a blanket that would cover all observable surfaces of an object that one seeks to cloak. Each display panel would contain an active-pixel sensor (APS) [or possibly another advanced image sensor] that would look outward from the panel through an aperture that would occupy only a small fraction of the area of the panel. The blanket would also contain a wiring harness that would include a cross-connected fiber-optic network, through which the image from each APS would be transferred to a complementary display panel on the opposite side of the cloaked object.
The positions and orientations of all the image sensors would be slaved to the position and orientation of one image sensor that would be designated a master imager. The orientations would be determined by a leveling instrument sensed by the master imager. A central controller connected to an external light meter would automatically adjust the brightness levels of all the display panels to make them conform to the to ambient lighting conditions. The underside of the cloaked object would be illuminated artificially so that the display from the top of the cloaked object would show the ground as though in ambient light; if this were not done, then an obvious shadow-induced discontinuity would be seen by an observer looking down from above.
The display panels could be sized and configured so that a common inventory of such panels could be used to cloak a variety of objects, without need to modify the objects. Sizes and weights of representative adaptive camouflage systems and subsystems have been estimated: The volume of a typical image sensor would be less than about 1 in.3 (≈ 16 cm3). A system to completely cloak an object 10 m long by 3 m high by 5 m wide would weigh less than about 100 lb (≈ 45 kg). If the object to be cloaked were a vehicle, then the adaptive camouflage system could readily be operated on power provided by the vehicle electrical system, without adversely affecting the operation of the vehicle.
The Scene From Behind an Object would be displayed on panels on the front of the object. The effect of cloaking is illustrated in this simulated image of an armored vehicle with adaptive camouflage on one side only.
This work was done by Philip Moynihan of Caltech and Maurice Langevin of Tracer Round Associates, Ltd., for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Electronic Components and Systems category.
NPO-20706
This Brief includes a Technical Support Package (TSP).
Adaptive Camouflage
(reference NPO-20706) is currently available for download from the TSP library.
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Overview
The document discusses an innovative technology known as Adaptive Camouflage, developed by Philip I Moynihan and Maurice L Langevin at the Jet Propulsion Laboratory under a NASA contract. This technology aims to render large assets, such as military vehicles, essentially invisible by projecting the scenery from one side of the asset to the opposite side. It utilizes advanced imaging sensors, specifically low-power, miniaturized focal-plane array imagers like Active Pixel Sensors (APS), and lightweight, rollable flat-screen displays.
The primary motivation for this development stems from the Department of Defense's need for improved camouflage solutions, particularly for stationary armored vehicles conducting surveillance. The proposed system addresses this need by creating a dynamic camouflage that adapts to changing environmental conditions, thereby enhancing the stealth capabilities of military assets.
The technology operates by linking electronic viewing devices with conformal displays, allowing for a seamless transfer of images from one side of a vehicle to the other. This setup can provide a 360-degree view of the surroundings, effectively making the asset invisible to observers from any angle. The system is designed to be flexible, with features that allow for selective cloaking, enabling friendly forces to see the cloaked vehicle while maintaining invisibility from enemy perspectives.
Key components of the system include small, inexpensive imaging sensors with a wide field of view, fiber-optic cables for high-resolution image transfer, and conformal flat-panel displays that can be arranged to suit various applications. The control system is lightweight and capable of coordinating the display panels to present coherent scenes or modify shapes to confuse enemy observers.
The document also outlines potential applications beyond military use, such as cloaking personnel or other objects. The envisioned system is designed to be lightweight, with a complete cloaking setup for a vehicle weighing less than 100 pounds, and a smaller version for human use weighing around three pounds.
Overall, the Adaptive Camouflage technology represents a significant advancement in stealth technology, combining innovative imaging and display techniques to create a system that can effectively conceal assets in various operational scenarios.
