Use case: move observations to tape

Purpose: record observations on D and C tapes.

Actors: observer, tape copier.

Outline:
The observer writes observations to the D-tape(s) during the observing night or at the end, before leaving the telescope to sleep. During the following day, the tape copier verifies the D-tape and copies the observations to the C-tape. When the C-tape has been made, the observation files are purged from disk leaving only the tapes and a copy in the INT data manager.