Thursday, February 12, 2009

Special Forces' Gigapixel Flying Spy Sees All

By David Hambling February 12, 2009

You may think your new ten-megapixel camera is pretty hot –- but not when you compare it to the 1.8 Gigapixel beast built for the Pentagon. The camera is designed as a payload for the A-160T Hummingbird robot helicopter now being quietly delivered to Special Forces. It will give them an unprecedented ability to track everything on the ground in real time. The camera is scheduled for flight testing at the start of next year.

Developed under the auspices of Darpa, the camera is the sensor part of Autonomous Real-time Ground Ubiquitous Surveillance - Imaging System or ARGUS-IS. The camera is composed of four arrays, each containing 92 five-megapixel imagers. The other parts of ARGUS are the airborne processing system, which has to deal with a phenomenal torrent of data, and the ground-based element. The airborne part fits into a 500-pound pod.

The Hummingbird is unique in its ability to hover at high altitude (over 15,000 feet) and its endurance of over 20 hours. This means it can park high in the sky and scan a wide area. Robo-chopper camera-maker BAE Systems says that its imager will be able to cover an area of over a hundred square miles. The refresh rate is fifteen frames per second and a "ground sample distance" of 15 centimeters –- this means that each pixel represents six inches on the ground. (The Darpa diagram, above, suggests a smaller area of coverage, 40 square kilometers or 15 square miles, at that resolution.)

The volume of data is too great to be completely transmitted, but users will be able to define at least sixty-five independent video windows within the image and zoom in or out at will. The windows can be set to automatically track items of interest such as moving vehicles. In fact, the resolution is good enough for it to offer "dismount tracking" or following individual people on foot.

In addition to the windows, ARGUS will provide "a real-time moving target indicator for vehicles throughout the entire field of view in real-time." Basically, nothing can move in the entire area without being spotted. Unlike radar, ARGUS can zoom in and provide a high-resolution image.

The camera is pretty impressive, but it's the processing and the software behind it that will make this such a capable system. It would take a human a very long time to scan the whole area under surveillance if they were looking for something – but this is exactly the type of task which the swarming software we looked at last week excels at. Luckily enough, that just happens to be a Darpa program too. The technique of looking at small windows of interest also means that it may be possible to speed the frame rate up considerably – we previously looked at a windowing system so fast it could follow speeding bullets.

The ARGUS-IS mounted on the Hummingbird could be a significant battlefield asset for getting a real-time picture of what's on the other side of the hill. And no doubt there will be civilian agencies who think it might be quite a useful capability for them to have too.

Mythological Footnote: Someone in Darpa may be a fan of the classics – Argus or Argos Panoptes was a giant, unsleeping watchman with a hundred eyes all over his body. Unfortunately he was killed by Hermes; according to the myth, his eyes were placed on the tail of the peacock.

[Image: DARPA]