Unable to get ImageSolver to work

At least if I have an image that won't solve on my primary PC I can jumpt over to my laptop and solve then use SPCC on my laptop. A bit clunky.
I haven't written code since I did Fortran in the '70s, so I can't inspect this to really understand what to attempt to fix. I just know that when I installed SPCC the plate solve stopped. Prior to the install I was able to solve [albeit I couldn't run SPCC lol].
I'm assuming you are always solving with ICRS.
When you select "automatic limit magnitude" it searches through the GAIA files (in magnitude order) until it finds a magnitude that give a "sensible" star count.
For each DR3 file it searches, it outputs a pair of lines like:

Gaia: Global context
x.xx us

(after the first pair of lines it outputs "Searching for optimal magnitude limit..." - but just ignore that)

If you have changed the GAIA preferences to only include the first four DR files ( files -01 to -04), then it should not be able to output more than 4 of the pairs of lines.
when it has finished searching, it outputs something like:

* Using an automatically calculated limit magnitude of yy.yy.

The question I was trying to answer is, with "automatic limit magnitude" checked, how many of these pairs of lines (i.e. how many times does it say "Gaia: Global context") before displaying the calculated limit magnitude, and what is this magnitude?

Gaia: Global context
5.200 us

Searching for optimal magnitude limit...

Gaia: Global context
159.713 ms

Gaia: Global context
163.791 ms

Gaia: Global context
203.859 ms

Gaia: Global context
192.762 ms

Gaia: Global context
198.483 ms

* Using an automatically calculated limit magnitude of 16.76.
* Using the automatically selected GaiaDR3_XPSD catalog.
Seed parameters for plate solving:
Center coordinates: RA = 11 19 55.000, Dec = +13 00 08.00
Resolution: 2.154 as/px
Starting StarAlignment iteration

Gaia: Global context
Executing Gaia DR3 search command...
3302 sources found.
195.726 ms
Catalog Gaia DR3 (XPSD): 3302 objects.
* Using the triangle similarity star matching algorithm.
BTW, the rejection maps for this image are like nothing I've ever seen. Were there clouds or headlights or something else that contaminated some of the source frames?
Just looked at them. Haha...must have been my headlamp looking down the scope. Pretty bad!
So it is now estimating the "correct" limit magnitude, so if it is still failing that suggests that the excessive star count wasn't the problem. Oh well, worth a try.
Here is an image I just solved: same setup [except no reducer] with just the 4 DR Gaia files without a hitch.


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Not that anyone cares, I re-ran my images through WBPP after I culled some of the "lousy" frames in Blink. I took out 10 frames. They really did not look that bad but to be safe...

During the current re-processing it popped up as an error as the metadata indicated a focal length of 360 mm [my fault during the imaging process in APT]. I changed the focal length to the correct number of 288 mm and the astrometry solved [see attached].

Here is a link to the image XISF: https://1drv.ms/u/s!AnnDQlrdkXW8g4su47v95jFEsygryw?e=7MboYj

Please notice that the rejection frames are better. Although that might have contributed to the issue it does not totally resolve why you all could plate solve the original image and I couldn't.

Lesson learned to be more cautious when choosing light frames and focal length.

Thanks again.


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Came across this long thread last week when I suddenly had the exact same problems with the Image Solver in PI as @cloudbait although I did a video in Feb 2023 showing how to use Gaia catalogue, image solve and then do the SpectrophotometricColorCalibration. Turned out I had moved the Gaia files to another drive (SSD drive) and that seemed to be the problem. After moving the files again to the default HD recognized by PI, it worked again smoothly.

However, I still couldn't run the SpectrophotometricColorCalibration afterwards. Image of NGC 6888 in RGB. If anyone is tempted to give it a try I can upload the xisf on OnDrive and post the link.

Thanks and CS


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