I ran into an issue the other night with the ASTAP plate solver not solving. I’m currently running SGP 3.1.0.454. I typically, for plate solving, run everything at 4x4 binning and never had a bad solve. All of a sudden, with beta 454 it fails to solves at a 4x4 bin. Platesolve 2 works without any issue at the 4x4 binning. also, ASTAP solves 1x1 binning without any issue. As I mentioned it appears to happen with this latest beta 454. I used ASTAP with previous betas and ASTAP plate solver always worked.
If I do a ASTAP plate solve by right clicking the 4x4 bin image and enter in the image scale, i my case 3.01, (4 x 0.752) it would solve. I’m just wondering if for some reason, something, like the image scale is not be sent from SGP to ASTAP during centering?
I currently switch back to Platesolve2, not my preferred plate solver. ASTAP is much faster. I can send logs if needed but they are on my observatory computer.
Agree, wonder why ASTAP would suddenly not solve but PS2 does? I’m open to any ideas. Is there some setting in ASTAP that might have gotten changed or corrupted? Maybe I should uninstall and reinstall ASTAP? Just looking for things to try. Obviously, if it was systemic others would be having this same issue so it has to be something that just happened with my setup. As I said, ASTAP was running just fine up until 454.
There is no reason why the ASTAP settings would change suddenly. It can only happen if you opened ASTAP and change some setting there. In that case start ASTAP, go to menu file, setting, settings to default.
In any case having solving problems go through this ASTAP checklist:
at least 30 stars are visible
reasonable round stars
image dimensions at least 1500x1000 pixels.
correct pixel size in arcsec specified
If PS2 is solving then point 4) should be okay because PS2 is more critical on pixel size. You could send me a link to the image so I can have a closer look. E.g. by uploading it to nova.astrometry.net and send me the link of the result.
Reasonable round stars - Yes, I always do an autofocus prior to any plate solving.
Image at least 1500 x 1000 - I assume this is unbinned? I always plate solve with binning at 4x4. for my ASI294 cambera that would put the image at only 1036 x 705 pixels. Below the recommended 1500 x 1000.
Pixel size in arcsec - Yes
For item 3 and 4, I assume that SGP is passing the image scale and binning to ASTAP. So it must be my binning that is causing the failure. I know for a brief second a message from ASTAP shows up that states something like image is too small. But what I don’t understand is that I’ve been using ASTAP for several weeks with this same camera and same binning and never had a failure up until 454. I guess I need to run the binning at 2x2. and give that a try. Not calling for any clear skies for several days. Once I get a break in the clouds I’ll try the 2x2 binning to see if that solves the issue.
You could check it with existing images so your ready for the next clear sky moment. Yes 1036 x 705 is too small. ASTAP will be much happier and reliable with a 2072x1410 image. ASTAP generates a warning message if the dimensions are too small, but I don’t think they are currently picked up by SGP
The reasonable round stars is about ovality and not so much about focus. In most cases the image is taken shortly after slewing and some mounts require 10 to 15 seconds before the slack is out of the gears and they are tracking again. Oval stars due to tracking failure will be identified as galaxies and ignored.
Just wanted to give an update. we’re having a surprising clear night tonight, a little windy but for the most part clear. I went to the same target as I did the night I had the plate solving issue and performed a bunch of ASTAP platesolve tests. at 1x1, 2x2, 3x3 and 4x4 binning and everything worked. even at the 4x4 binning ASTAP was able to solve everything. My only conclusion, it must had been the moon. the night I was having the plate solving failures with ASTAP might had to do with the almost full moon. maybe the bright moon was washing out too many stars.
Anyway, I just thought I would follow up to let you know all is working as it was before. Lesson learned, During a nearly full moon ensure there are enough stars and change the binning.