Flat Planning
(advanced users only)

Normally, ACP's automatic sky-flat system will be set up to take a fixed set of flat fields. If you are an advanced user, and want to take advantage of ACP's power features for sky-flats, you'll need to familiarize yourself with ACP's sky-flat system before you use ACP Planner to create flat plans. ACP's automatic sky-flat feature is extremely flexible, allowing you to make the best possible use of the available dusk and dawn time for taking sky-flats. The system is described on the web at Using Automatic Sky Flats. If you are a remote user, ask the observatory operator to help you. Henceforth, we'll assume you understand this feature.

noteBefore using flat planning, you must set up your filters in Planner's preferences to be in dusk order and enable flat planning. See Getting Started, Flat Planning Options .

Flat Plan Generation

ACP Planner can generate flat plans automatically. It does this by scanning your observing plan for all of the unique combinations of filter, binning, and (optionally) rotator angle that occur in your plan. Thus the flat plan tells ACP to take only the flats needed to calibrate the images in your observing plan.

Once the Enable flat plans preference has been turned on, ACP Planner will generate flat plans.

To generate a flat plan with Planner:

  1. Make your ACP observing plan as usual and select Save Plan...
  2. When the file-save window appears, enter the file name of your observing plan.
  3. In the file-save window, make sure you're saving your plan to your default Plans folder (My Documents\ACP Astronomy\Plans) or a sub folder under it (or see Flat Plan Name and Location below). Click OK.
  4. The generated observing plan will appear in Notepad. You'll notice that the #duskflat and/or #dawnflat directives will specify a flat plan file. Edit the observing plan if needed. Don't alter the #duskflat and/or #dawnflat directives, though. If you edited it, save it.
  5. Close Notepad.
  6. Now the generated flat plan will appear in Notepad. It will be named the same as your observing plan, except with -flat appended to the file name, and it will be saved in the same folder. Edit it if needed. If you edited it, save it.

If you saved your plan to your default Plans folder (or a sub folder under it) that's all you need to do!

noteUnless you really know what you're doing, save your flat plans in your default Plans folder or sub-folder thereof!

Note: The sensitivity of the filter/imager increases as the square of the binning level. Thus, higher binning translates to more sensitivity. So the generated flat plan starts with the lowest binning, then steps higher. It will list the filters in order of increasing sensitivity for the lowest binning, then again for the next binning. For example, though you have listed your filters in order Red, Green, Blue, Clear, a typical astro-imaging observing plan will have the Clear images at binning 1 and the other filters at binning 2. In this case, Clear will be listed first in the generated flat plan because it has images at binning 1 and the others don't

Flat Plan Name and Location (expert users)

So you're an expert. OK, here's the issue with saving observing and flat plans to other than the default plans folder: If you are running Planner on a computer other than the one that ACP is on, the folder paths that get put into your observing plan will probably be wrong. How do you know that the other computer has the same folder structure as yours? It probably doesn't! ACP and ACP Planner are smart enough to hide this from you if you use the default Plans folder. But if you don't, you're on your own.

If you have remote login set up in your current preferences profile, this option is disabled.

Moral: Don't turn on Specify File Name in the Flat Planning section of Preferences unless you're planning on your observatory computer. If that's the case, then Planner will put the full path to your flat plan file into the #duskflats and/or #dawnflats directives in your observing plan. Planner will also put a warning comment above these directives to tell you that your observing plan is not portable. If you don't get this, then just save your observing plans to your default Plans folder, and leave Specify File Name off. If you have unusual needs, post a note to the DC-3 Dreams Communication Center and we'll try to help.