NASA Studying Infrared Photography in Firefighting

Space-age technology may be used one day by firefighters to combat wildfires and plan controlled burns in the Santa Monica and San Gabriel mountains.

Research on the use of infrared photography in the prevention and control of forest fires is being conducted by the National Aeronautics and Space Administration (NASA), under the direction of James Brass, and the U.S. Forest Service, under the direction of Philip Riggin.

The two scientists began a filming project during a controlled burn last October in the San Dimas Experimental Forest and will soon carry out another one in the Santa Monica Mountains.

They are sharing their information with people such as Capt. Scott Franklin, a specialist in controlled fires for the county Fire Department, and representatives of the national and state parks and the county flood control district.

The two said that from altitudes of 30,000 to 60,000 feet, cameras loaded with infrared film can detect dry or diseased plants, track a fire’s progress, measure the heat of flames and soil and check on the regeneration of plants in a burned area.

Infrared film collects data that previously was obtainable only by trekking into hard-to-reach mountain brush areas. The data is read by sensors that can be tuned to eight different light bands, from the visible images of conventional film, to near-infrared, which picks up color, to thermal infrared, which picks up heat.

“We can use the visible portion to look at general land-cover characteristics, such as soil coloration, water color and how green the vegetation is,” Brass said.

And by moving sensors up the light spectrums and using a computer, Brass and Riggin can tell the dryness and age of plant growth and whether it is diseased.

Also, they said, the sensitivity of infrared film means that pictures can be taken from greater heights, making it possible to compare growth over large areas than with the piecemeal information now available.

Brass said that during a fire, pictures could be taken every two hours. The thermal channels would tell how hot the fire was and how long it was taking to cool. Such information is important to firefighters and others involved in forestry management.

To design controlled fires, Franklin said, he must know more about what happens to plants and soil during fires and at what temperatures the changes occur.

Some plants, he said, will reproduce only after old growth is destroyed and seeds have been exposed to the heat of a wildfire. But other plant seeds are destroyed by high heat. And with no new growth, rain will cause erosion.

“We are excited to be looking at fire effects by using the thermal channels,” Riggin said. “We want to see how hot the soil gets and how long it stays hot. We’ll make repeat flights, a few hours apart.

“The reason we’re interested is, the amount of soil erosion that happens after a fire depends on how much damage the soil undergoes during burning. The hotter the fire, the more heat applied to the soil surface, the more damage during burning.

“That’s one of the reasons we are interested in prescribed burnings. You can reduce soil overheating as opposed to what you see in catastrophic wildfires.

The scientists will begin filming this month in the Santa Monica Mountains, where they hope to find out how many plants are dead or dying.

“We want to be able to see how flammable a particular stand of chaparral is,” Riggin said. “Some are much harder to burn than other types. We want to know how much of the chaparral is chamiso, how much is lilac. Chamiso is more flammable than lilac.

“In terms of fire containment, it’s important to know how flammable the fuel is. The more precise the burn, the less chance of it exceeding the boundaries prescribed.”

Knowing what species will burn under different atmospheric conditions also helps firefighters select the types of plants they want to destroy in a controlled burn so that desirable, healthy trees or other growth are left alone.

In addition, Franklin said scientists are able to feed the data taken from infrared film into a computer to predict the course, speed and heat of any fire.

Scientists are working on a method of transmitting that picture directly from the aircraft to firemen on the ground.

NASA is interested in the global application of what Riggin and Brass are learning in the local mountains, Brass said.

“My interest is primarily in fires as they affect biochemical recycling,” Brass said. “The bottom line on that is, we are looking at . . . an ecosystem.”