Hey folks,

I’m not sure how to put this - I’ve spent the last 6 months just trying to get ASTAP to successfully solve one of my images. Tonight, I finally fixed that problem and ran face first into another problem.

I can success plate solve, and the software shows that the coordinates have successfully synced to the mount. But no matter how many iterations of plate solving I do, my position error never gets better than 20,000 arcseconds, which is totally unusable. I’m picking targets all over the sky away from the meridian, but it never gets any better. Does anyone have any suggestions?

A couple thoughts. First, if you have 20K arcsecs of error, you have a pretty serious clock or lat/lon config problem (or both). I would chase that down and fix it to ~1800 arcsecs or less (1/2 hour). Next thought: just because you platesolve doesn't necessarily mean the mount is receiving the results of those sync commands to update the pointing/alignment model. It's driver implementation specific as to whether this is done or not. In my case (Celestron CGX-L), I know the driver doesn't receive the commands. Thus, I just avoid defining a pointing model (N star align) altogether and platesolve align for each target. Totally acceptable speed and performance (especially if you download the index files and/or use the new StellarSolver). It really shouldn't matter which method you prefer. Both are perfectly usable. I know many folks that don't do an N star alignment at all....just polar align, and then slew/platesolve for each target, and it works great. Good luck...

Jake,

You will need to provide some log files.

There are three options with solving, synch, slew to and nothing, are you sure it has slew to set?

Paul

I’ll record the log the next I’m out with it. My options are “Sync”, “Slew to Target”, and “Nothing”. I’ve got the “Sync” option checked. Is that the correct mode to be in?

no....you want Slew to target. It might take a couple iterations depending on what your tolerance setting is. That said, you should definitely look for that 20K error and beat it down a bit. If you don't you'll make solving work harder than it should....

Jake,

Synch will only tell the mount where you are pointing.

There are two things you need to do

1) Choose and slew to a target and then.
2) Run plate solving with the Slew to Target option.

When you do this it will iterate as many times as required until it is within your configured accuracy - I use 30 arc seconds,

Regards

Paul