Since the array is read continuously, and without synchronization with the drive mechanism of the filter wheel, one exposure is lost at the beginning and at the end of the measurement at each point of the scan, this adds an overhead of at each point, or, for the complete scan, a total of:
The time needed to turn the filter wheel between two points is very short, and can be accounted for by the extra exposures added above.
There is a system constraint on the power dissipated by the instruments in the ISO focal plane unit which limits the frequency of activation of the motors to 6 position changes per minute.
One must add the overhead due to the DRK and CLN OPERATIONS when they have been selected.
Find corresponding to the selected dark procedure in Table or
min applicable.
= + + +