Each tape contains one week of Yohkoh data, and is either data for a new week, or is a re-reformatted version of some previous week. Each tape has label with a code like the following written on it:
95_22a.01-1.220 / | | | year | version | week reformatterThe "a" after the week and the "1." before the version number are reserved for future, unknown use and never change. The version indicates whether this is the first version of tape produced for the indicated week, or whether it is an updated version of the data for that week (i.e. a different version of the reformatter program was used). The reformatter number simply indicates which release of the reformatter software was used to process the data. The reformatter release numbers increment by 10. Sometimes a version number of "22" or "17" is written on the label instead of the proper "220" or "170". Thus if a tape was received at a later date with the code 95_22a.02-1.240, this tape would replace the tape above. The tape version number has been known to increase by more than one (from .01 to .03, for example), with no intermediary valued tape having been produced. A Lockheed mystery. The reformatter seems pretty stable now (Nov 95) and most tapes now are only for new weeks.
As each batch of tapes are received, the new tape code and production date are added to the list. If the tape is an updated version of an older tape already on the list, the tape code and date from the new tape are substituted for the older tape on the list. I also make a backup of the current list of tapes (current.yohkoh.tape_logs.backup) and a copy of the latest version before the most recent update (previous.yohkoh.tape_logs.backup). First edit the yohkoh.tape_logs file, adding the new tapes. Then copy the "current" file onto the "old" file. Then copy yohkoh.tape_logs onto the current file. Or in UNIX speak:
akala>% cd /solar/daily/Mees/tape_logs akala>% vi yohkoh.tape_logs #add new tapes akala>% cp current.yohkoh.tape_logs.backup previous.yohkoh.tape_logs.backup akala>% cp yohkoh.tape_logs current.yohkoh.tape_logs.backupThis way there are always got one or two backups in case things really get munged up and someone can always figure out which were the most recent tapes to arrive.