Polar Alignment no longer solving

Using SharpCap's Polar Alignment feature
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lattosimbaste
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Joined: Sat Mar 25, 2017 6:49 pm

Polar Alignment no longer solving

Post by lattosimbaste » Tue May 09, 2017 4:47 am

Hi Robin,

I'm at a bit of a loss to understand why but my setup is no longer solving- stars are identified and in sufficient number but no joy is being had. The images are solved just fine via TheSkyX so I suspect there's something strange happening that unfortunately will be difficult for me to troubleshoot due to weather here for the next few nights.

The setup is a 50mm finderscope with a ZWO ASI178 set to 2080 x 2080 binned X2 which should yield a FOV of 1 degree 23' square according to TSX. Sharpcap seems happy with the default settings and picks up stars easily but will never advance. The polar alignment of the mount was quite good to begin but perhaps it has settled a bit, TPoint reported alignment to within 2' of the NCP last week.

I can't seem to attach an image (reported as too large) but here's a link to one in google drive:

https://drive.google.com/open?id=0B8Ckr ... XFKRTJWdG8

Sorry for the lack of information but that's what I have for now. I'm a bit stumped, this worked well months ago down to FOVs of ~30' with another telescope.

Thanks in advance,
Bill Dean

admin
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Re: Polar Alignment no longer solving

Post by admin » Tue May 09, 2017 7:32 am

Hi Bill,

it's a bit noisy, so turning up the noise reduction settings is a good idea, but the real problem here is that you are too far from the pole!

Astrometry.net solves this frame at 81.9N (http://nova.astrometry.net/user_images/ ... #annotated), so the whole of the frame is outside the 5 degree circle around the pole that SharpCap has in its plate solving database.

cheers,

Robin

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Re: Polar Alignment no longer solving

Post by admin » Tue May 09, 2017 7:33 am

Just to clarify, SharpCap's plate solving database is a 5 degree radius circle around each pole, so it goes from 85N to 90N and 85S to 90S

cheers,

Robin

lattosimbaste
Posts: 5
Joined: Sat Mar 25, 2017 6:49 pm

Re: Polar Alignment no longer solving

Post by lattosimbaste » Sat May 13, 2017 5:02 pm

Thanks Robin, it appears that the heavy rain and high winds pushed the mount around quite a bit. I finally pulled the cover off this morning and found that the front leg of the tripod had slipped off a pad and onto the soil, very surprising considering the setup weighs well over 150 kg. Hope to have clear skies this weekend to try out the polar alignment routine again.

Best,
Bill

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Re: Polar Alignment no longer solving

Post by admin » Sat May 13, 2017 8:54 pm

Ah, a hardware problem - nothing wrong with the software after all :) :) :)

Hope you get it sorted!

cheers

Robin

lattosimbaste
Posts: 5
Joined: Sat Mar 25, 2017 6:49 pm

Re: Polar Alignment no longer solving

Post by lattosimbaste » Fri May 19, 2017 7:39 pm

Hi Robin,

Finally had a clear night and was able to fire up Sharpcap and get the mount aligned in under 5 minutes. Subsequently ran an automated model with TPoint and the polar alignment report corroborated the alignment to be within 30" of the NCP which is more than sufficient. Thanks again, great stuff.

Clear skies,
Bill

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Re: Polar Alignment no longer solving

Post by admin » Sat May 20, 2017 1:59 pm

That sounds better - also nice to get confirmation from another approach that the polar alignment is spot on!

cheers,

Robin

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