Sunday, July 14, 2013

More CCDAP evaluation: taking images

Back from GSSP, I want to evaluate CCDAutoPilot more. It was VERY handy at GSSP to take dusk flats. Although the problem that it automatically kicks in and starts taking dusk flats is still not fixed, it's still a very comfortable way to take flats.

I now wanted to try taking images. My first challenge was to set a target. There isn't an "add target" or such button on the main screen :-( After reading the manual, I found out that I can select (and center!) a target in TheSkyX and then with the "Get" button get it into CCDAP. That sort of works. It's just weird, that I have to center it (so that it is in the FOV). And then CCDAP labels the object FOVCenter - even in the image name.

Then setting all the parameters (binning, focus...) was very easy. I then started taking images:
  • The precision slew was working - but I think it shows the inaccuracy of the CGEM mount. Here is a sample log output:
    03:46:41 Precision slew try number 1
    03:46:41 Plate solving...
    03:46:41 Telescope RA: 22 37 45.3, Dec: +34 28 46
    03:47:29 C:\Users\Mark\Documents\CCDWare\CCDAutoPilot5\Images\SyncImages\Sync_20130714_034641.fit
    03:47:30 Stars: 86, FWHM: 2.7 arc-sec.
    03:47:30 Solved RA: 22 36 57.3, Dec: +34 26 48, PA: 172.0
    03:47:35 Sync'd to RA: 22 37 36.6, Dec: +34 31 03
    03:47:36 Telescope RA: 22 37 36.7, Dec: +34 31 03
    03:47:36 Telescope reports RA: 22 37 36.7, Dec: +34 31 03
    03:47:36 Plate Solve Time: 54.5 sec.
    03:47:36 Pointing error (arcmin): RA 2.0; Dec -1.6
    03:47:36 Telescope connected
    03:47:36 Slewing scope...
    03:47:44 Slewed to RA: 22 37 44.4, Dec: +34 29 28, Jnow
    03:47:44 Mount settling for 3 sec. after slew.
    03:47:49 Telescope tracking on
    03:47:49 Sync'd
    03:47:49 Plate solving...
    03:47:50 Telescope RA: 22 37 45.4, Dec: +34 28 46
    03:48:00 C:\Users\Mark\Documents\CCDWare\CCDAutoPilot5\Images\SyncImages\Sync_20130714_034750.fit
    03:48:01 Stars: 76, FWHM: 3.1 arc-sec.
    03:48:01 Solved RA: 22 37 05.5, Dec: +34 24 25, PA: 172.0
    03:48:07 Sync'd to RA: 22 37 44.8, Dec: +34 28 41
    03:48:07 Telescope RA: 22 37 44.9, Dec: +34 28 40
    03:48:07 Telescope reports RA: 22 37 44.9, Dec: +34 28 40
    03:48:07 Plate Solve Time: 17.2 sec.
    03:48:07 Pointing error (arcmin): RA -0.1; Dec 0.8
    03:48:07 Try 1 slew error: 48.1 arc-sec
    03:48:07 Precision slew try number 2
    03:48:08 Telescope connected
    03:48:08 Slewing scope...
    03:48:16 Slewed to RA: 22 37 44.4, Dec: +34 29 28, Jnow
    03:48:16 Mount settling for 3 sec. after slew.
    03:48:22 Telescope tracking on
    03:48:22 Sync'd
    03:48:22 Plate solving...
    03:48:22 Telescope RA: 22 37 45.4, Dec: +34 29 22
    03:48:33 C:\Users\Mark\Documents\CCDWare\CCDAutoPilot5\Images\SyncImages\Sync_20130714_034822.fit
    03:48:34 Stars: 87, FWHM: 2.8 arc-sec.
    03:48:34 Solved RA: 22 37 05.4, Dec: +34 25 09, PA: 172.0
    03:48:39 Sync'd to RA: 22 37 44.7, Dec: +34 29 24
    03:48:40 Telescope RA: 22 37 44.8, Dec: +34 29 24
    03:48:40 Telescope reports RA: 22 37 44.8, Dec: +34 29 24
    03:48:40 Plate Solve Time: 18.1 sec.
    03:48:40 Pointing error (arcmin): RA -0.1; Dec 0.1
    03:48:40 Try 2 slew error: 5.8 arc-sec
    It took 3 attempts and 2 minutes to get the error down to 5.8 arc-secs. But at least it worked.
  • Focusing with every new filter didn't work at all. The focus degraded from sequence to sequence. When I analyzed the @Focus2 log files, these are the first focusing graphs that I got:



    The first two are completely useless. The third one makes sense and leads to a correct focus. So, I'll have to work on my @focus2 routine to make it more robust.
    I should try to use the recommended focus range of 4500 to catch the outer, lower areas of the graph. Will do that tonight.
    I worked on the @Focus2 parameters and could create a rock-solid process. It converged and worked all the time. I think the problem is that when @Focus2 is invoked from CCDAP, it does not slew to an appropriate star, but tries to focus where the scope is pointed to. Will need to investigate further.
  • A weird bug(?) I found was that I can't enable tracking through TheSkyX (in the Telescope->Tools menu). Which is annoying, because CCDAP likes to put the scope into parking and then disable tracking...
  • And of course, I have to figure out guiding with CCDAP.
  • The good thing was the automatic meridian flip that CCDAP does.
But if I figure all this out, this will make taking images way easier. So, tonight, I'll work on the @focus2 routine and then try this out again.