June 12, 2013
Landsat 8 Images Made Available To Public And Researchers Alike
Watch the video "Landsat Looking At El Paso, Texas"
Brett Smith for redOrbit.com - Your Universe Online
More than 40 years after the launch of its first satellite, the Landsat program continues to deliver comprehensive and publicly available satellite imagery. Earlier this month, images from the program´s latest satellite Landsat 8 were made available via the Internet.
“These are scientific data, as much as they´re beautiful images,” said Doug Morton, a physical scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
For the past few months, scientists from NASA and US Geological Survey have been working to properly calibrate the instruments on Landsat 8 so that the new images are not only accurate but also consistent with previous Landsat imagery.
The newest satellite is expected to collect a minimum of 400 images per day, which will be archived at the USGS facility in Sioux Falls, South Dakota. Archived images are made available to the public for free over the Internet just days after being taken.
Landsat data have been used for a variety of commercial and academic purposes, including observing agricultural yield, water use and forest fires across the US. Modern computer processing power has allowed researchers to take a longer, wider and more refined look at the satellite imagery.
“The ability to use every image in the archive has revolutionized the way we do science, conduct business and share information worldwide,” Morton said. “Instead of picking an anniversary date — like the middle of summer — and looking at that date over as many years as there are cloud-free data available, we´re starting to mine every pixel in the archive.”
Despite changes in processing power, many of the uses of the imagery have remained the same, according to Bruce Cook, Landsat deputy project scientist at Goddard.
“It´s still inventorying natural resources, still looking at their utilization,” Cook said. “It´s still looking at the interactions between people and their environment.”
“But now you´re talking about a world population that has doubled, almost, since the first Landsat. So there´s even more pressure on our natural resources, and more reason to be studying these things.”
Besides looking at standard photographic images, researchers can also make use of Landsat 8´s Operational Land Imager, which detects nine different spectral bands. This information can be used to track the health of the vegetation on the ground and changes in flora composition.
“A scientist, looking at these images, sees more than initially meets the eye,” Morton said. “The information in different Landsat bands allows scientists to quantify subtle changes over time — the response of a forest to droughts, the change in reflectance as a forest canopy grows taller and more variable over time. We see that ecosystems are changing all the time, and Landsat data captures these changes like no other program in the world.”
Landsat information has also been used to track changes in the atmosphere over time, from the amount of pollution hanging over the Midwest to the effects of climate change. Since the program´s somewhat humble beginnings 40 years ago, scientists have culled more and more information from the program´s growing database of images, Morton said.