With their ability to pick out humans by their heat signatures, long-wave infrared (LWIR) thermal imaging cameras are a valuable asset for soldiers – and alien predators. Unfortunately, non-alien built ones are expensive and so large that they need to be mounted on vehicles. In an effort to make a LWIR camera cheap and small enough for an individual soldier to carry, DARPA is working on a five-micron camera that offers a reduced size without sacrificing performance.
Developed in association with DRS Technologies, Inc., the five-micron LIWR camera uses a 1280 x 720 focal plane array (FPA), which is a relatively high resolution for an infrared camera. Yet it’s smaller than conventional cameras because, at five microns across, each pixel is about one twelfth the width of a human hair and around one sixth the size of current state-of-the-art devices. In a first for an infrared camera, the pixels are also about half the size of the photons it detects.
The approach it takes is similar to that of a phone camera, which also uses smaller pixels to provide higher density in a compact package. By using smaller pixels, more can be placed on a single chip while maintaining the same level of sensitivity, resolution and field of view. And since the cost of FPAs is proportional to chip area, they are also cheaper.
According to Nibir Dhar, DARPA Program Manager, “DRS built three fully functional prototypes as part of this DARPA work. The cameras have been tested for various applications, including peering through particles in the air, which would be useful for helicopters landing in brownout conditions. We have found that the image is crisp and the performance of these FPAs is comparable to those with much larger pixel sizes.”
The LWIR camera was developed under the Advanced Wide FOV Architectures for Image Reconstruction and Exploitation (AWARE) program, which is also responsible for a gigapixel camera prototype.