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We need to develop a policy for split nights. Changing modes induces a thermal transient which affects subsequent RV measurements, so we should avoid this unless it is well motivated scientifically.
Procedures
If The SA for the night is responsible for making sure that the read mode gets switched to fast for the appropriate section of the night and for switching it back to normal when appropriate. Even if a night (or portion of a night) is fast read mode, we need must to take the normal set of daily calibrations as normal ( in normal read mode) to maintain our knowledge of the instrumentinstrumental drift and wavelength solution.
In addition to the normal calibrations we need to switch in to fast read mode and take a set of fast read mode calibrations (primarily biases, but also darks if time allows). This is probably best done after regular scheduled cals are finished (usually around 5:30pm HST) and before sunset. This can be a very narrow time window at some times of year.
After Automated Afternoon Cals Finish
To change modes use kpfSetReadModeFast
.mode to fast run: kpfSetReadModeFast
Then run the cals using: kpfRunCalOB -f /kroot/rel/default/data/obs/kpf/FastReadoutCals.yaml
This OB executes 22 biases (to match our normal daily set) and 1 dark (we’d like more, but we likely won’t have time). The dark frame can be canceled if needed in favor of observing (using the usual methods for stopping an OB in progress).
After Fast Read Mode Observations are Done
To change modes use kpfSetReadModeNormal
as appropriate.mode back to normal run: kpfSetReadModeNormal
This must be done before the normally scheduled cals begin at 7am HST.
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