New data tools watch forests from space

New computing technology allows satellites to reveal small changes in a forest that can lead to big changes in its ecosystem, NASA says. Called LandTrendr, the computer program is able to find patterns previously buried within vast amounts of scientific data, and has already analyzed satellite imagery to reveal an obscured, slow-moving decline and recovery of trees in Pacific Northwest forests, the space agency reported Tuesday. The unexpected disturbance pattern showed a long slow decline of tree health over years followed by slow regrowth, and comparing satellite data to ground data allowed scientists to finally uncover the cause. "It was, as it turns out, bugs," Robert Kennedy, a remote sensing specialist at Boston University, said. LandTrendr is made possible by computers that are finally powerful enough to process vast amounts of data contained in data from NASA's Landsat satellites, which have been observing Earth's land surfaces since 1972. The U.S. Geological Survey began providing Landsat data for no charge in 2008, but researchers had to wait for computers powerful enough to chew on all that data. "Not that long ago the size of an individual Landsat scene would have crippled most desk top computers," Doug Morton at NASA's Goddard Space Flight Center in Greenbelt, Md., said. The ability to scroll backward and forward through 40 years of data has revealed slow and subtle changes that take place over many years, including pulses of insect outbreaks, Kennedy said.