Infrared imaging is used for a range of military applications - such as target acquisition, night vision, homing and tracking - which means that any vehicle with some kind of infrared "invisibility cloak" would hold significant advantages on the battlefield. BAE Systems has tested just such a technology that not only allows vehicles to blend into their surroundings, but can also let it mimic other vehicles or natural objects.

Dubbed "ADAPTIV," the patented infrared cloaking technology developed at BAE consists of sheets of hexagonal panels that act as pixels when attached to the exterior of the vehicle. These pixels can individually change temperature very rapidly and combine to display an infrared image of the background scenery captured from cameras onboard the vehicle, allowing even a moving tank to match its surroundings. BAE has also put together a library of images to display the heat signature of other vehicles, such as cars, trucks, and natural objects, such as large rocks.

The hand-sized hexagonal panels are made of lightweight metal so they can sustain physical impact and provide defense against enemy ordinance. They are heated and cooled using commercially available semi-conducting technology and are electrically powered by the vehicle's systems. They are also designed so that damaged panels can be easily removed and replaced.

BAE says it has focused mainly on the infrared spectrum because this is the most important to the Swedish Defence Materiel Administration (FMV), which funds part of the work. However, it has also combined the pixels with other technologies, which provide camouflage in other parts of the electromagnetic spectrum to provide all-round stealth. It plans to further develop this technology over the next few years.

"Earlier attempts at similar cloaking devices have hit problems because of cost, excessive power requirements or because they were insufficiently robust," says project manager, Peder Sjölund. "Our panels can be made so strong that they provide useful armor protection and consume relatively low levels of electricity, especially when the vehicle is at rest in 'stealth recce' mode and generator output is low."

As well as ground vehicles, such as tanks, ADAPTIV can also be used on ships, aircraft and fixed installations. The pixels can also be resized to achieve stealth at different ranges. A warship or building, for example, might not need close-up stealth, so could be fitted with larger panels to display a lower resolution image.

BAE conducted trials in mid-July in which one side of a CV90 Swedish infantry fighting vehicle was covered in the panels and was made effectively invisible or appear to be a 4x4 vehicle when viewed in the infrared spectrum from distances of 300 to 400 m (984 to1,312 ft). BAE will display the CV90 with ADAPTIV technology at the UK Defence and Security Equipment International exhibition later this month.

A video showcasing the ADAPTIV technology can be viewed on the BAE Systems Website.