The EOSDIS provides the total ground system for processing, archiving, and distributing science and engineering data from all the EOS spacecraft. EOSDIS also provides the mission operations systems that perform the functions of command and control of the spacecraft and instruments, health and safety monitoring, mission planning and scheduling, initial data capture, and Level 0 processing. Command of all the EOS spacecraft and instruments is done at the EOS Operations Center located at NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland.

Data from the Terra spacecraft will flow via the Tracking and Data Relay Satellite System (TDRSS) to the TDRSS ground terminals in White Sands, New Mexico, where the data will be captured and recorded at 150 Mbps. The data will be forwarded via a 45-Mbps communications link to the EOS Data and Operations System (EDOS) at GSFC where they will undergo Level 0 processing, which includes elimination of transmission errors and artifacts, separation of the raw data by instrument packet identification, removal of duplicate packets, and generation of Level 0 production data sets (period covered is specified by the customer). Level 0 data sets for four of the five instruments (MODIS, CERES, MISR, and MOPITT) will then be transferred (over the EOS networks) to the appropriate Distributed Active Archive Center (DAAC) for further processing, utilizing algorithms provided by the Instrument Science Teams. Level 0 data for the ASTER instrument will be sent via physical media to the ASTER Ground Data System (GDS) in Tokyo, Japan, for further processing. A set of ASTER Level 1 data products will be sent via physical media from the ASTER GDS to the EROS Data Center (EDC), where it will be processed to produce higher level data products.

Eight DAACs representing a wide range of Earth science disciplines have been selected by NASA to carry out the responsibilities for processing, archiving, and distributing EOS and related data, and for providing a full range of user support. The EOSDIS utilizes a system-wide EOSDIS Core System (ECS) that provides uniform support across all DAACs for these activities.

The DAACs shown in the following table will process and archive the data from the Terra mission. Distributed Active Archive Centers DAAC Location Discipline Instrument EROS Data Center (US Geological Survey) Sioux Falls, South Dakota Land processes data ASTER, MODIS Goddard Space Flight Center (NASA) Greenbelt, Maryland Upper atmosphere chemistry, atmospheric dynamics, global biosphere, hydrology, and geophysics MODIS Langley Research Center (NASA) Hampton, Virginia Radiation budget, clouds, aerosols, surface radiation, land processes, and tropospheric chemistry CERES, MISR, MOPITT National Snow and Ice Data Center (University of Colorado) Boulder, Colorado Snow and ice, cryosphere, and climate MODIS Computing facilities used by the EOS investigators are called Science Computing Facilities (SCF). These facilities range from individual workstations to supercomputers. They are used to develop algorithms and models for the generation of data products, to access services in EOSDIS, to conduct scientific research, and to perform scientific quality control of the data products. Some SCFs support the planning, scheduling, command and control, and analysis of instrument engineering data. Additionally, each EOS instrument team has its own SCF. The main SCFs for Terra data are shown in the table below. Science Computing Facilities ASTER Jet Propulsion Laboratory (NASA) Pasadena, California CERES Langley Research Center (NASA) Hampton, Virginia MISR Jet Propulsion Laboratory (NASA) Pasadena, California MODIS Goddard Space Flight Center (NASA) Greenbelt, Maryland MOPITT National Center for Atmospheric Research Boulder, Colorado Teams of scientists world-wide have already been selected to receive the data to perform research in areas of international concern. Additionally, EOS data and products will be available to all users, without restriction, at no more than the cost of dissemination, regardless of the intended use. Processing Levels Level 0 Reconstructed, unprocessed data at full resolution; all communications artifacts have been removed Level 1 Level 0 data that has been time-referenced and annotated with ancillary information, including radiometric and geometric calibration coefficients, and geolocation information Level 2 Derived geophysical variables at the same resolution and location as the Level 1 data Level 3 Variables mapped on uniform space-time grids, usually with some completeness and consistency Level 4 Model output or results from analyses of lower level data