Exactly one hour to plate solve?

[Greg Sellek]

Hi Bob,

Not sure if this behavior was introduced with our MaxIM update to 6.10 or ACP update to 8.0 build 5 , but suddenly it's taking exactly one hour to plate solve our images during a run. If I use MaxIM to plate solve manually, it only takes a few seconds. The 'exactly' one hour thing has me thinking it's a bug somewhere. Log from last night attached. This happened after every image.

03:36:25 (exposure complete and image downloaded)
03:36:27 Image finished
03:36:48 Plate-solve final image
03:36:55 30323 image stars found
04:36:55 701 catalog stars found
04:36:57 Solved! 205 stars matched.
04:36:57 Average residual is 0.24 arcsec.
04:36:57 Pointing error is 0.357 arcmin @ angle 189.80
04:36:57 True focal length is 2966.1 mm.
04:36:57 True binned plate scales (arcsec/pix): H = 0.63 V = 0.62


Thanks as always,
Greg

[Bob Denny]

Ultra strange. The one at 06:40:50 solved in 10 seconds. It would have been good if you hadn't killed the run right then. It seems to have taken exactly 1 hour between detecting the image stars and looking up the catalog stars. At least the first two times. And the pointing exposure solutions, as well as those in FocusMax, are solving fast.

I'm in the car on the way to AIC. I'll try to research this with a remote login to my desk. I want to see what's happening in the area of the delay. This should be interesting...

[Bob Denny]

OK, this logic is really old and has not changed in years. What you see cannot be related to MaxIm in any way, nor related to upgrading ACP. Plus it isn't doing it all the time. I was able to get to my desk and look. There are only a couple of calls to PinPoint, that's it. I'm stumped.

ImageUploadedByTapatalk1444935841.452287.jpg

[Dick Berg]

Hi Greg,

I am wondering if you tried or would try to solve either image outside of the ACP environment, for example using MaxIm's plate solving. You can set up MaxIm's parameters to match those of ACP. It would be helpful to know if MaxIm also takes an hour.

It's reasonable to see 30000 image stars in your wide field 20 minute exposure. The GSC has about 400 stars per square degree averaged over the whole sky. For your .55 square degree image there would on average be about 200 stars, but you're looking deep into the MW, so finding 700 stars is probably right, too. It's not surprising that the solution times were identical, since ACP found the same 701 stars both times. It is however hard to imaging what would cause it to take an hour, especially since the pointing image immediately before took only a couple of seconds with 590 catalog stars. Binning 4, however, not binning 1.

Is your camera a color "one-shot" CCD? If so, in MaxIm, if it still takes a long time to solve at binning 1, do a bin 2x2 (Edit menu I think - I'm not looking at MaxIm right now) and then see if it solves faster.

I'm still thinking about this, too. It might be helpful to know if this problem exists at some other nearby place in the sky, still in the MW, and maybe also somewhere not in the MW.

Is this the first time you've encountered this problem?