When Terra, one of the satellites in NASA's Earth Observing System (EOS), began beaming data back to Earth last year, it became the first satellite to simultaneously monitor many of the Earth's natural systems on a daily basis. Equipped with a wide array of instruments, Terra offers new perspectives on the Earth's land, ecosystems, radiation, and life forms and gives insight into how these systems interact and influence each other. Scientists all over the globe marveled at the quantity and variety of the data gathered by Terra.













"When I first saw the data that was coming in, I felt a mixture of relief and excitement," recalls Bruce R. Barkstrom, a researcher at NASA's Langley Research Center and a principal investigator on Clouds and Earth Radiant Energy Systems (CERES), which is part of NASA's Earth Science Enterprise Program. "Relief because everything was working; excitement because the instruments seemed to be working much better than we had ever expected."

The satellite is part of a long-term effort that seeks to understand our planet, distinguish between natural and man-made climate changes, and predict the effects of global warming. Two more EOS satellites—Aqua, which will concentrate on water systems, and Aura, which will gather atmospheric data—will be launched over the next two years. Each of these satellites will beam about two terabytes of data to Earth each day, a volume that presents mind-boggling data-management challenges.

"You've got all kinds of instruments on those satellites that will be collecting data on just about every kind of natural system related to the Earth," says Mike Folk, technical program manager of the Hierarchical Data Format (HDF) group at NCSA. "You need software that can accommodate all these types of data and allow scientists to share it, independent of platform."

NCSA HDF is that software. Since 1994 NASA has been committed to using HDF for storing and managing all the data gathered by its EOS sensors. Other organizations that use HDF as the standard file format for their research data include the Department of Energy's Accelerated Strategic Computing Initiative (ASCI), and the National Oceanic and Atmospheric Administration's National Geophysical Data Center. NASA's Landsat satellites also use HDF.

Access Online | Posted 3-27-2001