Plate solving?

Discussions of using SharpCap for Planetary Imaging
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devonshire
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Plate solving?

Post by devonshire » Mon Nov 11, 2019 4:41 pm

I'll be upgrading my guide camera shortly, and this will free up my GPCAM2 IMX224 for planetary work w/Sharpcap, as opposed to BYN + D5300, which I've been using on DSO's.

One of the things I use on every DSO session with BYN is the plate solving integration w/Astrotortilla. Very nice, both for finding and framing the targets after CdC gets me close.

Although I currently use Sharpcap only for PA, I do understand that it can plate-solve, and I hope to get that working as part of controlling the IMX224 in its planetary imaging role (Imaging scope: EDT refractor, 102/621mm, assume barlowed for planetary).

BUT... what I'm not clear on is how best to use that for framing, when my target is a planet. Pick a nearby star? Advice?

Thanks!

- Bob

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admin
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Re: Plate solving?

Post by admin » Mon Nov 11, 2019 9:04 pm

Hi,

That might be tricky because when you are imaging the planets your field of view tends to be very small, which means there may not be enough stars for the plate solving algorithm to work well.

It will turn to be worth a try though... Just tell your planetarium software to go to the planet, then use the plate solver and re-sync button in the telescope controls in SharpCap – first making sure you can see 20 or so stars in the frame which will properly need you to set high gain in a few seconds of exposure at least. As long as you've got the data installed on AstroTortilla for small fields of view and enough stars are visible then the plate solving should locate where the telescope is pointing and then correct the pointing to bring the planet in to view. I must admit though that I've never tried this with a planetary camera/scope setup.

Cheers, Robin

devonshire
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Re: Plate solving?

Post by devonshire » Mon Nov 11, 2019 9:59 pm

Thanks, Robin!

Well, it is all about FOV, however one centers, isn't it? :-)

Which indexes did you have in mind for this? :
"As long as you've got the data installed on AstroTortilla for small fields of view..."

- Bob

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Re: Plate solving?

Post by admin » Tue Nov 12, 2019 6:51 pm

Hi,

When you install AstroTortilla, it asks you about installing the index files for different fields of view – the smaller the field of view you want to cope with the more data needs to be downloaded and installed. If you want to add more index files for smaller scales then I think you can just run the installer again.

Cheers, Robin

BlackWikkett
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Re: Plate solving?

Post by BlackWikkett » Wed Nov 13, 2019 2:45 pm

Here's an excellent Astrotortilla installation and setup guide. It's a few years old but still relevant.
https://www.lightvortexastronomy.com/tu ... lving.html

TimHaymes
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Re: Plate solving - which solver ?

Post by TimHaymes » Thu Aug 27, 2020 1:39 pm

I'm posting a reply here as i dont seem to be able create a new topic, but the subject is similar. I believe I have plate solving working now. In the process of testing I have two solvers installed. All SkyPlate Solver (ASPS) and Astrometry.net Local Server which has ansvr. Both apps have there own set of index files. When I set up SC plate solve settings i use AstroTortilla/Ansvr/ASPS as the preferred plate solver.

The question: If SC is using one or other of the two solvers installed, and how do find out which it is ?

Looking at solve field tool setting, the automatic detect is: c>users>Tim>Appdata>Local>Astrometry>bin>solve-field
Is this All Sky Plate Solver ?

The most positive outcome of the solved field are the OBJ coordinates, which are written to the FITS file header - very helpful.

Tim

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Re: Plate solving?

Post by admin » Thu Aug 27, 2020 6:22 pm

Hi,

in the current version the best thing to do is to perform a plate solve and then look in the log to see what the path to the plate solving application was (search the log text for "running external command").

I've seen a number of issues recently where people have had trouble because their plate solving application setup is complex or incomplete, so I have enhanced SharpCap to provide more details in the plate solving settings and to also check for common problems (no index files, out of date Astap version, etc). This will be in the next update SharpCap 3.2.

Cheers, Robin

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