Satellites used to detail crop damage

DEKALB, Ill. -- Satellite photography, best known for monitoring the weather or reconnaissance by the military, is finding a niche in the agricultural sector.

Researchers at Northern Illinois University have used data from a National Aeronautics and Space Administration satellite orbiting more than 400 miles above the earth to estimate the cost of crop damage from two hail and wind storms that hit west-central Illinois in the summer of 1999.

"This could become the preferred method for assessing crop destruction from any natural or man-made disaster," said Mace Bentley, the NIU meteorology professor who headed the study.

The long-range photos provide an unprecedented level of detail and accuracy in reviewing crop damage, he said.

"The previous way to estimate damage was to make a drive-by estimate. That misses a lot of the damage," he said.

With images from the Landsat 7 satellite and special software, color-coded images are able to identify changes in ground reflectance pointing out where crops have been destroyed by thunderstorms, tornados and other disasters, Bentley said.

Spatial mapping of agriculture could be used by farmers, insurance companies and meteorologists who could examine storm formation and downburst potential, he said.

Bentley said damage from the 1999 storm was estimated at $57 million at the time, but satellite research shows an estimate of more than $100 million. He said actual losses were less since some blown-down crops were salvaged.

While obtaining satellite photos isn't cheap, at $600 a shot it's a dramatic reduction in cost, said Bentley. Pictures used to cost $3,000 to $4,000 each.