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  1. #1
    Join Date
    Mar 2014
    Location
    Rowe, New Mexico
    Posts
    143

    Default Scheduler flats not behaving as as expected

    Bob:
    We've made significant progress and have imaged 3 nights with Scheduler. Flats acquisition is still a bit of a mystery given that the dawn flats have not behaved as expected. Scheduler has taken only the Ha and O3 flats that are listed in the ScehdulerDawnFlats plan (I've yet to run Dusk flats). Here's the plan (stored in the plans folder):

    ; Format = #, Filter, Bin, Rotation
    ;
    3, B, 1, 270
    3, G, 1, 270
    3, R, 1, 270
    3, L, 1, 270
    3, H, 1, 0
    3, O, 2, 0

    I expected Scheduler to start with B and work its way through the order until it completed or ran out of time. On each of 3 imaging runs it has produced just the H and O3 flats. AutoFlatConfig.txt is set up and is stored in the ACP\Config folder. The attached shows the flats taken last night, the locations and content of the files involved (i.e., AutoFlatConfig, SchedulerDawnFlats, ScheulerDuskFlats). There are quite a few text files to set up. Perhaps I missed one?

    What would make Scheduler skip filters B through L? Is something wrong with my AutoflatConfig? Or with the Dusk or Dawn flat plans?

    ~~~~~~~~~~~~~~~
    The rest of this discusses observations that may or may not be pertinent to the above questions:

    I also noticed the date/time stamps show the O3 began first followed by H even though there are in the opposite order in the flat plan.

    I also noticed a small detail: the filter name that is part of the file name has a lower case "o" instead of "O"--the filter is named "O" (uppercase). This may not matter, but these days I look at every detail--this could indicate it's looking at the wrong flat plan.

    Also of note is the direction in which the flats were taken. I assumed the mount would follow the solar null at dawn (and even dither?), but going by the time order 2 flats were taken in the East, then 4 in the West, the 2 more in the East. I again assume this is normal and that Scheduler was trying to attain the specified ADU; however, it seems to me that the proper point in the sky would always move towards the west away from the rising sun unless the filter density called for more light. In my case there were 2 H flats taken in the West and then 2 in the East. This is explainable but unexpected.


    Thanks, Lloyd
    Attached Files Attached Files

  2. #2
    Join Date
    Mar 2014
    Location
    Rowe, New Mexico
    Posts
    143

    Default

    I might have solved part of this based on a thread that I read....you'll see in the file folder screen shots that I still had a defaultflats file in the folder. I understand that this might cause a problem. Tonight's test will tell.

    -Lloyd

  3. #3
    Join Date
    Mar 2014
    Location
    Rowe, New Mexico
    Posts
    143

    Default

    Turns out that the change I made above didn't have a positive affect on flat production. In fact, flats didn't run at all. As another solution I tried to use the web forum to submit a flat plan. I'll run the testing procedure this afternoon, but this generated yet another question. The plan generated does not include rotation angle even though it's specified.
    Flat plan through browser.JPG

    Well, I'll answer this myself...the rotator must be connected in ACP otherwise the PA doesn't get picked up.

  4. #4
    Join Date
    Oct 2005
    Location
    Mesa, AZ
    Posts
    27,051

    Default

    Lloyd --

    As always, I don't expect everyone to read all of the help info word for word... but I do point people to the info covering their questions, so take this in the right spirit!!

    From ACP Help, Automatic Flat Fields, Flat Plans
    Quote Originally Posted by ACP Help
    The format of the flat plan is one line per flat set. A flat set consists of a combination of count, filter, binning, and (optionally) rotator equatorial position angle, in that order separated by commas. The order of flat sets must be as they would be taken at dusk - with the filter/binning resulting in the lowest sensitivity used first (when the sky is brightest).
    This is also clearly described in the slide-out help on the One-Time and Set Up Scheduler flats web items (see screen shot of One Time item below, Set-Up Scheduled has same help).

    Quote Originally Posted by you
    What would make Scheduler skip filters B through L? Is something wrong with my AutoflatConfig? Or with the Dusk or Dawn flat plans?
    It ran out of time. You can see this in the log file (which wasn't part of your package so I couldn't highlight that info). It starts with the last one at dawn.

    I also noticed the date/time stamps show the O3 began first followed by H even though there are in the opposite order in the flat plan.
    Same issue. It's running in dawn order but the plan must list them in dusk order.

    I also noticed a small detail: the filter name that is part of the file name has a lower case "o" instead of "O"--the filter is named "O" (uppercase). This may not matter, but these days I look at every detail--this could indicate it's looking at the wrong flat plan.
    I'm not sure why... I looked at the code and can't see any case-changing. I would have to get on to your system and see it.

    Also of note is the direction in which the flats were taken. I assumed the mount would follow the solar null at dawn (and even dither?), but going by the time order 2 flats were taken in the East, then 4 in the West, the 2 more in the East. I again assume this is normal and that Scheduler was trying to attain the specified ADU; however, it seems to me that the proper point in the sky would always move towards the west away from the rising sun unless the filter density called for more light. In my case there were 2 H flats taken in the West and then 2 in the East. This is explainable but unexpected.
    It's not really taking them in the east or west, it is rotating to the mechanical rotator angle needed to achieve the requested PA as if the mount looking east or west. The East and West you see in the names reflects this, not the actual position in the sky at which the flat is acquire - that would not work at all! It does follow the solar null with dithering. Note that ACP was the first automation program to have this feature (sky flats) in production. From ACP Help, Acquiring Images Automatically, Automatic Flat Fields, Rotator Support section:

    Quote Originally Posted by ACP Help
    With rotator support, if the telescope is a GEM, half of the flats in each set are taken with the rotator at the specified PA and the other half are taken 180 degrees from the specified PA. This allows making flats for the common case where the target crosses the meridian/flip-point, invokes ACP's auto-flip feature, and thus has a 180 degree rotation in the middle of acquiring its images. The west and east images require flats with rotations 180 degrees apart.

    This splitting of flats can be suppressed by setting the advanced parameter NoAutoFlipRotatorPA to True in AutoFlatConfig.txt (Advanced Users section).
    -- Bob

  5. #5
    Join Date
    Oct 2005
    Location
    Mesa, AZ
    Posts
    27,051

    Default

    I just called Lloyd to close the loop, and he says things are running great with Scheduler all around. The only issue is occasional guide failures, after dithering. When I worked with them last week online, I noted that their Field of View Indicator (FOVI) was off a fair bit. So it would be conceivable that (a) they used the FOVI to put a guide star in the middle of the sensor, yet (b) it actually ended up closer to an edge due to the FOVI errors, then (c) a dither (even an auto-dither) could initially move the guide star right off the sensor, resulting in guiding failure. He's going to look at the FOVI which right now was constructed from the QSI specs and not validated against reality.
    -- Bob

 

 

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