A Sharper Image Finds Fire Faster

The U.S. Forest Service eyes a new remote-sensing system to detect early flames.

This month, imaging scientists Donald McKeown and Michael Richardson of the Rochester Institute of Technology are test-flying a $3 million fire-mapping system to help the U.S. Forest Service spot fires earlier.

Dubbed WASP, the NASA-funded Wildfire Airborne Sensor Program is the first of its kind to combine infrared heat-sensing cameras, a high-resolution visible-light digital camera equipped with spectral filters and advanced GPS equipment. When mounted to a gimbal in an aircraft’s belly, the cameras will sweep from horizon to horizon along the flight path, detecting new wildfires or mapping existing ones from 10,000 feet.

WASP is likely to be a welcome innovation. The 2002 forest fire season was among the most devastating in years, with three states suffering worst-on-record blazes and $1.6 billion spent squelching fires from Arizona to Montana. Tests show WASP could help fire crews catch budding flames before they spawn infernos. Its trio of infrared cameras scan a broader band than current Forest Service equipment does. They can detect a fire as small as a foot across–hardly big enough to generate smoke. The cameras also pick up “cool” fires, those smoldering at about 600ºF, barely above the temperature at which dry wood begins to burn.

WASP has several advantages over current fire-detection systems. First, it integrates more sensitive fire-detection capabilities with geospatial positioning data. Fire managers will be able to download real-time data on a fire’s location and surrounding geography from WASP, enabling them to dispatch GPS-equipped fire crews with tremendous precision to a small fire–and give crews advance warning about growing spot fires caused
by flying embers. “We’ll be able to correlate every pixel to a place on the ground, longitude and latitude, so we can go from image to a map,”says McKeown.

Another plus is that WASP will be able to detect fires during the day, when current infrared cameras would likely pick up false readings. “There is some interesting physics going on in fire, and we have had some real breakthroughs,” Richardson says. “We found that there is a very strong emission due to potassium that is excited when a fire burns. That’s a unique signature that allows you to discriminate fire from something like a piece of metal in the sun.” The researchers will discern potassium emission by using a special filter fitted to the digital camera.

A final plus: cost savings. WASP employs state-of-the-art commercial equipment rather than custom-built gear. “What we have now are one-of-a-kind systems that can be hard to maintain,” says Tom Bobbe, manager for the Forest Service’s remote-sensing office in Salt Lake City. The new gear, says McKeown, is a big improvement over equipment now deployed. “The stuff
the Forest Service uses now is about 15 years old, and it’s almost impossible to find parts for it when it breaks down,” he adds.

After McKeown and Richardson’s summer flight in a two-engine Piper Aztec over charcoal test fires and other small heat sources, they plan to borrow a U.S. Forest Service aircraft to test the system over prescribed burns. If WASP proves useful, it could be in full-time operation aboard Forest Service aircraft based in Boise, Idaho, by 2005.

Yet WASP is only the beginning of a revolution in the use of remote sensing to manage fire. The Holy Grail of fire managers, says Lloyd Queen, a remote-
sensing expert at the University of Montana, is to integrate satellite-based fire-detection systems with vegetation maps and new-generation weather models that develop faster, more accurate forecasts. Such a system could help experts determine if a newly spotted fire might pose a real risk to towns or resources such as watersheds and should be contained, or whether it might best be allowed to burn.