Platesolve fails near celestial NP

Image processing, astrometry, photometry, etc.
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Rudi
Posts: 102
Joined: 08 Jan 2019, 04:47

Platesolve fails near celestial NP

Post by Rudi » 14 Feb 2021, 20:54

The other day I was going close to the celestial north pole, and found, that Astroart couldn't platesolve.

Horizontal field = 93.6 arc minutes
Pixel resolution = 1.2 arcsec per pixel
The fit file:
https://www.dropbox.com/s/gjn5bdo21a0aa ... e.fit?dl=0

All my settings in Astroart regardi ng star detection are fine, any other fit solves perfectly.

I even tried expanding ra/dec limits to make a blind solve (size ra = 360 and size dec = 180), but no luck.

Having an idea about the math behind, I could imagine, that an image containing the celestial NP could cause some challenges.

Any suggestions how to make Astroart platesolve this?
/Rudi

fabdev
Posts: 253
Joined: 03 Dec 2018, 21:43

Re: Platesolve fails near celestial NP

Post by fabdev » 15 Feb 2021, 15:50

I checked, you're correct, plate solve is not possible near the poles (Dec > ~89). It will be fixed in Service Pack 6 available next month. The problem was indeed the singularity of the pole coordinates.
If you need the prerelease now, let me know by email or PM.
Thanks, Fabio.

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Rudi
Posts: 102
Joined: 08 Jan 2019, 04:47

Re: Platesolve fails near celestial NP

Post by Rudi » 15 Feb 2021, 18:22

Thanks for the quick reply Fabio 👍

No rush, I’ll just wait for the next SP
/Rudi

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Rudi
Posts: 102
Joined: 08 Jan 2019, 04:47

Re: Platesolve fails near celestial NP

Post by Rudi » 03 Mar 2021, 20:22

Solves fine now with SP6 - thanks!
/Rudi

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