Instrument
Performance
Assuming that the standard science data dump operations at the 32 kHz rate apply, it will take a constant 3.9 minutes plus a variable component to transition from the absolute time tag to stop an exposure to the absolute time tag to start the next one. The variable component depends on the mode change required and can be up to another 3.5 minutes for the worst case with the F/96 relay (4 filter wheels) to 1.9 minutes for the worst case with the F/48 relay (2 filter wheels). Thus, it could take up to a total of 7.4 and 5.8 minutes of time between successive exposures with an average of approximately, 6 and 5 minutes for the F/96 and the F/48 relays, respectively. In some specific situations, it may be advantageous, in order to save time, to take multiple exposures without closing shutter or dumping science data. Up to 11 consecutive exposures of this type can be made. If no changes to FOC mechanisms are required, the time interval between exposures can be reduced to 23 seconds total. This is the fastest rate at which the FOC presently can be run provided the telescope can be slewed to a new position on the detector quickly enough to permit it.
All the overhead times reported here are to be considered approximated, and should not be used for an accurate calculation of the required time (See the Proposal Instructions for a detailed and accurate description of all the relevant overheads).
Generated with CERN WebMaker