@freestar8n wrote:
I did some centering tests with cge-pro to see if the various offset methods work - and the results were somewhat odd and I'm not sure what is happening under the covers. Here are my observations:
First - the original python code I wrote some time ago to use sgp to center on objects works fine. It is very simple code and doesn't rely on sync - and it centers to within a few arc-seconds in about 3 iterations. So the mount is capable of centering very accurately when using sgp's infrastructure.
Sync None: This caused a somewhat up and down result that was under 100 pixels in dec., but ra would vary from about 22 to 3600 pixels - up and down.
Target Offset: This went to about 80 in RA and 12 in dec. and stayed there
Scope offset: This was under 20 in dec but ra rapidly increased: 117 104 859 858 7626 7679 7702
There were two additional observations:
If you don't use one of the "Sync Behaviors" that does a sync, then even when you do a manual "Solve and Sync" - it appears not to tell the mount to sync. Did you intend that? I pictured centering to be able to use sync or not - but when you actually do a manual solve and sync - it should always sync the mount. It looks like the only way to sync the mount is to change the sync behavior to sync - and then do solve and sync.
The second observation is that the hint given to the plate solve is not what it should be. Whether the mount is syncing or not, sgp should always have a good idea of where it is actually pointing. But during the centering process it kept using a hint that was the same value many arc minutes away from the target - even though it was centering on the target. This caused the solves to take a long time.
I know some people have said the solves take a long time - and if they aren't using sync then this may be the cause.
The math for what I use to center the cge-pro is extremely extremely simple. It just looks at the last error between where it was sent to and where it solved and adjusts the next move based on that. I think there is a chance "scope offset" is almost doing the right thing but there is a sign error making it move away.
So it looks like the new centering methods still aren't working - but maybe there is a sign error. And I think that solve and sync should always do a sync - and it's up to the user to know if the mount can handle that or not.
Frank
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