The Remote-Controlled Airplane Grows Up
The Remote-Controlled Airplane Grows Up
12 October 2007
published by www.photonics.com
USA — The latest wildfire-fighting aircraft is not designed to carry water. Instead, it is loaded with a thermal-infrared detection system. Because wildfires generate a lot of smoke and often burn in remote locations, firefighters can see little from the ground. Until recently, limitations in aircraft endurance, sensing equipment and communications devices have restricted the amount of information that aircraft-based surveillance could provide.
NASAs Ikhana, a Predator B remotely piloted aircraft, flies over smoky terrain during a wildfire observation mission.
To improve this, scientists from the Wildfire Research and Applications Partnership Project, including those from NASA Ames Research Center in Moffett Field, Calif., from the US Forest Service and from the National Interagency Fire Center in Boise, Idaho, have teamed up to put a specially designed wildfire-sensing system on an unmanned long-endurance aircraft with real-time communications equipment. During flights, conducted from mid-August through September at NASAs Dryden Flight Research Center at Edwards Air Force Base in California, the team demonstrated the aircrafts ability to collect data for 12 to 24 hours and to deliver real-time images to fire-incident commanders.
A NASA asset created by General Atomics Aeronautical Systems Inc. of San Diego, the Ikhana is based on the Predator B unmanned aerial vehicle that was designed for the US Air Force in the mid-1990s. The Ikhana is equipped with a digital electronic engine controller that makes it 10 percent more efficient than the earlier Predators. It has a 66-ft wingspan, is 36 ft long and can carry more than 400 lbs of sensing equipment internally and more than an additional 2000 lbs in external underwing pods.
Thermal-infrared images taken of the Zaca fire in California during the morning (left) and the afternoon (right) of Aug. 16 illustrate the fires progress. Courtesy of Vincent G. Ambrosia of NASA Ames Research Center.
Unlike helicopters that must be grounded at night and traditional airplanes that are limited by the amount of time their crews can work, the aircraft can fly for up to 24 hours and monitor in one trip several fires over a wide area. Pilots operate the aircraft from a ground control station in a mobile trailer that contains a remote cockpit, computer workstations and a satellite communications system. They uplink flight commands and downlink mission data.
In addition to increased sky time, the Ikhana features an autonomous modular scanner called the AMS Wildfire sensor. Designed by scientists from NASA Ames, the system scans 12 spectral channels ranging from the visible bands through reflective, mid- and thermal infrared. Unlike body-heat-sensing equipment typically used by security professionals, the device is calibrated to observe fires and other high-temperature sources, discriminating 0.5 °C increments up to 1000 °C.
At 20,000 ft and 2.5 mrad, spatial resolution is 50 ft. Still, because fire is so much hotter than the surrounding area, the system can detect even a small campfire from high altitudes. In a 16.5-h flight over Idaho, Montana and Wyoming, the scientists collected 15 GB of raw data and 131 processed images over six wildfires.
Much of this technology is commercially available off the shelf. It just needed to be put together, said the principal investigator, Vincent G. Ambrosia of California State University, Monterey Bay, in Seaside.
Even the most sophisticated data is useless unless it can be delivered efficiently. For this purpose, the Ikhana is equipped with a satellite data link that allows real-time transfer of fire imagery. Information is transmitted to NASA Ames, where it is available to the National Interagency Fire Center, among others.
This unmanned aircraft can send real-time data around the clock so that incident commanders can redeploy resources or get firefighters out of harms way, Ambrosia said.
