Scheduler has options for acquiring automatic flat fields at dusk and/or dawn. Before using this feature, be sure to read ACP Help, Automatic Flat Fields. At the appropriate time (see Concepts: Observing Run (night) Time Line), the scheduler will request that ACP do an auto-flat run using one of the following flat plan files as input:
These flat plan files must be located in the ACP local user's default Plans folder (typically My Documents\ACP Observing\Plans).
To activate automatic flat fields, enable the appropriate option on the Scheduler main window.
The problem with taking flats when using the scheduler is that you don't know what observing plans will be run during the night, so you don't know exactly what sort of flats are needed for the acquired data. If you don't use a camera rotator, the problem is solvable by setting up a standard set of flats that cover the range of binning and filter selections that could possibly be used. Since time is limited during twilight flat acquisition, you'll probably have to split up the flat requests between dusk and dawn. It's not necessary to take new flats every day either, so you could rotate flat plans (via file renaming) and acquire them on a rotating basis.
Again, be sure to read ACP Help, Automatic Flat Frames. Order is important for sky flats (not for panel/screen flats). Flats for each filter are listed in dusk order – in order of increasing sensitivity to the flat sky (which is very blue!). Also, binning 2 is 4 times as sensitive as binning 1. The format is count, filter, binning (comma separated, spaces insignificant). Here is a typical flat plan:
; ; Sample flat plan ; 3, HAlpha, 1 ; Narrowband at both binnings is... 3, HAlpha, 2 ; ... less sensitive than others
3, Clear, 1 ; Clear at binning 1 is least sensitive
3, Red, 2 ; Red is least sensitive in flat sky
3, Green, 2
3, Blue, 2 ; Blue at binning 2 is most sensitive
This plan probably would not complete in time; it is just an example. As you can see it's pretty simple! If you have a camera rotator, a 4th value must be on each line — the sky position angle (PA) of the camera.
Once you have your SchedulerDuskFlats.txt and SchedulerDawnFlats.txt plans in place, you should run them via the Scheduler's Utility menu, Test Dusk Flats and Test Dawn Flats items. If ACP is set up for panel/screen flats, you will may actually get usable flats (depending on light leakage in the building). If ACP is set up for sky flats, temporarily enable ACP's Simulated Images option. This will allow you to test your flat plans at any time day or night. The resulting images will not be usable flats, but the process will run.