Galileo Spacecraft Pages
Appendix B. SEDR Files (continued)
2. Interface Characteristics
Volume and Size
The volume and size of the F&P SEDR shall depend upon the frequency of output records required to maintain science pointing knowledge requirements via linear interpolation of data between adjacent records. Each logical record from GSOC shall contain 108 32-bit words of information, while JPL SEDR logical records shall contain 378 32-bit words. The frequency of output records shall be from one record per minute or real time image (RIM) count of the spacecraft clock (60 2/3 seconds) during close encounters to once per several hours during orbital cruise to one or two records per day during interplanetary cruise.
The frequency of output F&P SEDR records shall be negotiated with the F&P PIs and shall be determined by the highest required rate among those investigators.
Interface Medium Characteristics
GSOC generated F&P SEDRs shall be written to magnetic tape as the second file on the tape. The first file shall contain the EDR data to which the SEDR data applies. Magnetic tapes shall be written to be compatible with the F&P PI home institution host computers.
The JPL generated F&P SEDR shall be maintained as a database file on a local resident computer with planned local and remote access available to users in the future. Current plans call for the database to be written to magnetic tape and mailed to the F&P PI home institutions. The magnetic tapes shall be written to be compatible with the user host computer system.
Failure Protection, Detection, and Recovery Procedures
File Backup Requirements. GSOC will be responsible for the archival of all EDR/SEDR data they generate during the interplanetary science cruise phase until the end of this phase (JOI - 60 days) and all data has been transfered to JPL for permanent archiving. To facilitate the transfer of EDR/SEDR data from GSOC to JPL, GSOC will deliver the SEDR information (along with EDR data) they generate to JPL on approximate six month centers. At the end of the phase, GSOC will write the remaining data to tape and mail these to JPL within 60 days. Upon receipt of this last data (approximately the JOI time frame), JPL will assume archival responsibility.
GSOC will be responsible for the replacement of tapes which become damaged, lost, etc. at the PI institutions during the period for which they have archival responsibility. Replacement tapes will be mailed to PIs in the same manner as the original tapes. After JPL assumes archival responsiblity for the GSOC generated EDR/SEDR data, they will assume the responsibility of tape replacements. In addition to the GSOC data, JPL (GLL DMT) has archival and replacement responsibility for all SEDR data they generate in support of Jupiter orbital operations.
End-of-File (or Medium) Conventions
All F&P SEDR magnetic tapes shall be terminated with two (2) EOF marks after the last valid SEDR logical record.
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Updated 9/13/04, T. Hunt-Ward