Dspital 2022/10/09 02:05:54 Mount slews to target position: RA:2h28m50s DEC:+62°7'36"
2022/10/09 02:06:56 Exposure 5.0s
2022/10/09 02:07:06 Plate Solve
2022/10/09 02:07:10 Solve succeeded: RA:2h51m25s DEC:+61°42'2" Angle = 89.8604, Star number = 980
2022/10/09 02:07:10 [AutoCenter|End] Too far from center, distance = 503%(2.69091°)
Ah, so this looks like your problem. Nothing to do with plate solves.
A Meridian Flip is performed by issuing a GOTO command to the mount once the target has transited the Meridian. It looks like ASIAIR succeeded in doing that (from the second plate solve)and also suceeded plate solving.
So, no need to check exposures, focus, etc. Your plate is good.
Recall that the GOTO will cause the mount to perform a "blind" movement. I.e., it will move its motors by certian amount of degrees. Just like the initial GOTO at the beginning of the night.
Blind GOTOs are never that precise (unless you use a perfectly synced high end mount). And this is where plate solving comes into play. After a "blind" GOTO, you plate solve to find where the telescope is really pointing. You then sync the plate solve position to the mount, and that gives a new reference position for the mount, so that when you do small movements from that point on, it with be quite accurate, since it is referenced to that sync'ed location.
However, this does not hold true when you do a GOTO where the mount goes through a Meridian flip. That too is a blind GOTO, but it involves inverting coordinates (this is why you need to "flip" the autoguiding pulses after meridian flipping).
How accurate the blind GOTO ends up after a Meridian flip depends on how well the mount itself is initially positioned -- i.e., is the polar axis (RA axis) perfectly pointed at the pole, and does the mount knows the horizon perfectly.
The first parameter depends on how well you have polar aligned.
The second parameter depends on how well the mount has modeled its own horizon (cheap mounts don't even do that modeling very well). For some mounts, this is usually done by performing a multi-star "star sync" at the beginning of the evening. This will show the mount's model where it is really pointed to the sky for different motor angles. If you don't do multi-star sync, you should at least do a single star sync and make sure that your mount is perfectly leveled against the horizon in both the north-south and the east-west directions (especially the latter -- 1º off from east-west leveling will cause 2º worth of error when meridian flipping).
It could also well be that there is some weird bug in ASIAIR related to your mount. But check out on the accuracy of a Meridian GOTO flip first -- that might be your main problem. Definitely do a multi-star sync at the start of the evening, or if you are too lazy to do a multi-star sync, do a single star sync and make damn sure you mount's base is perfectly level with ground. Unless you have a mount with an absolute encoder (or a precise and calibrated index mark and a relative encoder), a star sync is needed.
You can do some simple checks. For example GOTO a star on the east, use plate solve to center the star and sync to that position. Next, make sure that Auto Center is turned off. Then execute a GOTO to a star in the west -- whereupon the mount should execute a meridian flip to get there, but will not do any re-centering by itself. Now plate solve the west star and look at the RA and declination values of the center of the plate (remember, with auto center turned off). If RA of the plate is off compared to the RA of the star, you have an east-west leveling problem. If declination is off, you have a north-south leveling problem.
Note that if RA of the blind east-west meridian flip is off by 1 degree, that will also cause auto meridian flips to be off by 4 minutes of time (i.e., the mount may appear stuck for 4 minutes of time before an auto meridian flip occurs).
Chen
