The International Solar-Terrestrial Physics (ISTP) program, like other missions, handles many different types of data. ISTP is an international project involving multiple spacecraft and ground-based experiments from the United States, Japan, Europe, and through the Inter-Agency Consultative Group (IACG) Russia. These missions provide more data types than ordinary missions; for example, there are Geotail Sirius data; level zero data for GEOTAIL, WIND, POLAR, the Solar and Heliospheric Observatory (SOHO), and the Interplanetary Monitoring Program (IMP) 8; multiresolution orbit and attitude data; quick-look data; Near-Real-Time data; housekeeping data; Key Parameter; Summary; and ancillary data.
It was recognized early on that management of these many disparate data types would significantly add to the cost and complexity of the data system unless a standard method of handling the data could be found. ISTP project personnel conducted a study of available methods and standards for data handling and metadata capture and adopted Standard Formatted Data Units (SFDU) developed by the Consultative Committee for Space Data Systems (CCSDS) with significant input from NSSDC/NOST. The SFDUs are separate header files, one associated with each data file. The ISTP/Central Data Handling Facility (CDHF) extracts information from the SFDU file to populate its data base, including the type of associated data, the source, descriptor, discipline, start and stop times, generation date and any accompanying notes. The information is used to catalog the accompanying data without actually opening the data sets or without being concerned with the format of the data files.
The CDHF has benefited from the use of SFDUs by simplifying the interface between the data files and the catalog, and the software required to support the system. The CDHF wrote their own specific software for writing and reading SFDUs and has made this software available to the ISTP community, thereby encouraging the further use of the standard.
Erin D. Gardner, email@example.com, (301) 286-0163
Hughes STX, Code 633, NASA Goddard Space Flight Center
Greenbelt, MD 20771, U.S.A.