NASA - National Aeronautics and Space Administration

The DRL serves the global Direct Readout community on behalf of the Terra mission objectives.  As the "Portal" for Terra mission information, technologies and algorithms, the DRL enables the global Direct Readout community to view Terra Earth monitoring data for real-time applications. 

The DRL receives the Terra MODIS direct broadcast transmission and generates data products for each overpass observed.  The products are then published to the Recent Data Products Gallery on the DRL Web Portal. (Terra products from the Remote Sensing Applications Center [RSAC] and Oregon State University [OSU] may also be viewed at the Gallery.)  The algorithms used to generate these products were provided by the mission and ported by the DRL and other mission development teams.  The DRL implemented these algorithms for use in a Direct Readout environment. These Terra algorithms, in Science Processing Algorithm (SPA) form, are available for free download via the DRL Web Portal. SPAs function in two modes:  Standalone, or as an International Planetary Observation Processing Package (IPOPP) plug-in.  The IPOPP data processing framework is also available for free download via the DRL Web Portal.

Terra Direct Readout Technologies, Data and Services

• Technologies
  Software and Algorithms to process Terra data
• Recent Terra Data Products
  Terra data products generated with IPOPP technologies
• Latest MODIS Image
  Quicklook Images from MODIS Instrument Instrument created with Simulcast
• MODIS Level 0 Data
  Archive of Production Data Set (PDS) file pairs
• Example Terra Data
  Provides example of composite frame data stream and example of MODIS data
• Latest Ephemeris
  TLEs from NORAD and IIRVs from Terra Project (updated every 24 hours)
• Terra X-Band Downlink Schedule
  Indicates times when Direct Broadcast mode will be turned off
• DSN Contact Schedule
  Terra turn-off times due to DSN activity (click here for information on how to read the schedule)

Documentation

• Interface Control Document Between the Earth Observing System (EOS) Data and Operations System (EDOS) and the EOS Ground System (EGS) Elements.  CDRL B301.  510-ICD-EDOS/EGS.  Revision 1.  January 1998.  (PDF)
• MODIS Command, Telemetry, Science and Engineering Description.  Document Number 151840.  May 1997.  (PDF)
• MTPE/EOS Data Products Handbook, Volume 1, TRMM and AM-1.  Ed. S.W. Wharton and M.F. Myers.  NASA.  1997.  (7M PDF)
• (Preliminary) Direct Access System Users Guide for the EOS-AM Spacecraft (ICD-107).  IS20008696.  November 1998.  (PDF)