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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

plate solving issues

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I'm having trouble using the new topic editor.  Is there any documentation anywhere?  I'm gonna try <code> and hope it doesn't screw up again.

<code>I can use Ekos on my mac to plate solve and polar align.  I'm trying to switch to a Pi and plate solving is failing. 

I can point my 'scope' at the sky, plate solve with the Pi and have it fail, then immediately switch to mac without changing anything and the mac plate solve works.

To investigate this I've been trying to create a reproducible test case of an image that I can use load and slew to plate solve that will work on the mac but fails on the pi.  And load and slew is behaving in an unexpected way, even on the mac.</code>

I have the same image , laptop-3, in 3 formats. 
  • a .fits file captured and stored by the ekos camera module
  • the matching .CR3 raw file (from the camera SD card) from which the .fits file was derived
  • a .fit file produced by using Siril to convert the .CR3 raw file from the camera to .fit format

Load and slew will solve the .CR3 file, the Siril produced .fit file but not the .fits file saved by the camera module.  Log file attached of load and slews of those three files in that order.

For the first two files 8 solvers with different fields of view are created.  "Solver # 2, Low 2.91094, High 11.3438 arcminwidth" succeeds. 

I'm guessing that 2.9x to 11.34xx is the range of field of view widths the solver will search.  The scope's fov width is about 10.3 degrees (200mm lens, full frame sensor) so that is what one would expect.

For the third file, only one solver is started with a scale range of "Scale range: 17.6923 to 26.5384 arcsec/pixel" which is wrong (if I've interpretted the log correctly).  And the single solver fails.

Presumably something in the fits header (attached) tells it to restrict the search.  I may have misconfigured something to cause an error in the fits header.  I know the scope aperture is wrong 74 instead of  50, but that doesn't seem like a likely cause.

Any thoughts on what might cause this behaviour?

 
Last edit: 2 years 4 months ago by Brian McBride. Reason: adding missing attachement
2 years 4 months ago #77148
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Replied by Jasem Mutlaq on topic plate solving issues

Thanks Brian, can you please post links to both Siril .fit and KStars .fits files?
2 years 4 months ago #77152

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Replied by Brian McBride on topic plate solving issues

Hi Jasem,

Thanks for looking at this.

Both files are in this directory:

drive.google.com/drive/folders/1HMoOwa8I...AYkkLPOf?usp=sharing

Brian
2 years 4 months ago #77154

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Replied by Jasem Mutlaq on topic plate solving issues

The issue was in position, the position reported in the FITS file is wrong. It's reported as RA 46.32 and DEC -0.08 so for some reason the mount position from EQMod was not recorded correctly. As to why, I'm not sure. Can you test again and inspect the FITS file again to see if the headers are still showing wrong RA/DEC values?
2 years 4 months ago #77158

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Replied by Brian McBride on topic plate solving issues

That would be operator error.

When the image was recorded Ekos didn't know where the telescope was pointing. Possibly held the result of an old plate solve.

When asking the solver to solve an image, I was expecting it to do it blind. My bad.

I'm assuming my guesses about what the scale numbers in the logs meant was not too far off? Is there anything I can read about how the solvers work and how to interpret the logs (other than the code)? I'll ask my favourite search engine.

Possible enhancement would be to have an option to force a blind solve. Probably not worth the extra complexity in the UI or the effort..

Now that I know what's going on I can get on with investigating why the Pi is not plate solving captured images.

Thank you for your help.
2 years 4 months ago #77164

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Replied by Grimaldi on topic plate solving issues

Make sure „use position“ and „use scale“ are NOT ticked in the settings (see Screenshot). Further check your version, before 3.5.5 these settings were ignored when the fits file on Load&Slew contained header infos.

 
2 years 4 months ago #77224
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Replied by Brian McBride on topic plate solving issues

Thank you for the suggestion Grimaldi.

It turns out it is exactly those settings that were causing the problems I was having on Pi which I now have working, polar alignment and all. I'm pleasantly surprised by how quickly it solves. Now if I could persuade it to download the images a bit quicker. Working on that.
2 years 4 months ago #77226

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