LP DAAC Archive Crosses Petabyte Threshold

On Nov. 20, 2003, the NASA's Land Processes Distributed Active Archive Center (LP DAAC) data archive holdings at the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) in Sioux Falls, South Dakota, crossed the one petabyte threshold in volume. One petabyte represents 1,125,899,906,842,624 bytes. A petabyte is the equivalent of 500 billion standard-size document pages, or 100 times the data volume of the U.S. Library of Congress.

"This is a major achievement for the LP DAAC," said DAAC manager Tom Kalvelage. "While the data volume is significant as an archive and distribution challenge, the importance rests primarily with the critical science information represented by the massive volume."

LP DAAC was established as part of NASA's Earth Observing System (EOS) Data and Information System (EOSDIS) initiative to process, archive, and distribute land-related data collected by EOS sensors, thereby promoting the interdisciplinary study and understanding of the integrated Earth system. The role of the LP DAAC includes the processing and distribution of ETM+ data acquired by Landsat 7, higher-level processing and distribution of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data, and the distribution of Moderate Resolution Imaging Spectroradiometer (MODIS) land products derived from data acquired by the Terra and Aqua satellites.

The EOS Core System was built to handle the large data flows associated with these Earth-observing missions, and was established at EROS in 1998. The system now includes numerous servers, three tape silos, and 45 tape drives. Over 1.5 million lines of custom software code were written to operate the system. Several robotic tape library systems provide near on-line storage for science data. High data transfer rates are made possible through advanced network connectivity solutions. These support administrative and system control as well as transfers of bulk science data as it is ingested from data providers and staged for distribution to science users.

Launch dates and data availability information for the several satellite missions supported by LP DAAC are summarized in Table 1. Launches took place during the period 1999 through 2002, and initial data releases have occurred from 1999 through 2003. As of Nov. 1, 2003, over 9,000,000 individual satellite images are available for distribution to a global customer base. Data collection is anticipated to continue for six years after each launch date. An average of one terabyte of data ingest occurs daily, with peaks of two terabytes. Data distribution to customers has exceeded 1.5 terabytes per day.

Visit the LP DAAC webpage for additional information concerning available data products.

Table 1 - LP DAAC Satellite Missions Supported and Data Available