Platesolve versus Platesolve and sync

[tjey]

I ran into a weird issue tonight that I haven't seen before, and I'm not sure how to troubleshoot what's going on.

I ran a "Platesolve", ASTAP would happily solve the frame, and give me the coordinates. However, if I did a "Platesolve and sync" I would get an error saying "Too many stars, try reducing the gain or exposure time" (Not the exact error message, as I didn't make a note of it). Reducing the gain or exposure didn't seem to make any difference.

Any tips on how to troubleshoot this further?

Thanks in advance.

[admin]

Hi,

if you want, feel free to share the SharpCap log from the affected session and I will see if there is anything I can work out from it. The only cases I can think of which might lead to a difference is if the mount co-ordinates are a long way off or if you are live stacking at the time.

Also, it's worth trying SharpCap 4.1 as there are improvements to Astap interactions and also there is a new 'Logging' setting to allow detailed logging of interaction with the plate solving appication which is designed to help track down this sort of issue.

cheers,

Robin

[tjey]

Thanks Robin!

I've uploaded the log in question here: https://drive.google.com/file/d/15xh4mW ... sp=sharing

The last few plate solve (and sync) are failures, but the scope didn't move from the one that was successful at 22:19:41.992329 in the log.

If there is other info/log/etc. that I can collect to help figure out what is going on, I'm glad to do so.

I hope the problem is in front the keyboard!

[admin]

Hi,

I think what had happened was that somehow the mount co-ordinates had become very different to where the telescope was actually pointing in the sky. The plate solve at 22:19:41 reports that the solved location was offset by 59.6 degrees from the hint location (which comes from the current mount co-ordinates) - the same for other plate solve only attempts at around the same time.

Code: Select all

Info   	22:19:41.992227	#1 	22:19:41  Solution found: 20: 20 12.6	+17° 58 19	 Solved in 2 sec.	 Δ was 59.6d.	 Mount Δα=-100.4d,  Δδ=23.0d. 	 Used stars down to magnitude: 11.1				

If you do a plate solve + sync then SharpCap restricts the search to within 15 degrees of the current mount co-ordinates on the assumption that this is to refine position, so the position should initially be roughly right. Obviously with such a big error, Astap will not find a solution within 15 degrees of the hint position.

Of course, now the question might be 'how did the mount end up being 60 degrees' off, but it seems that the plate solving was working as it should have.

cheers,

Robin

[tjey]

Thanks Robin!

I'll take a look at what's going on with my mount alignment.