I have never been able to successfully do a meridian flip and continue tracking and imaging. I’ve narrowed it down to two bugs with ASIair Pro software that need to be resolved:

  1. First, when connected to a ZWO filter wheel, if I have narrow band filters, they will prevent stars from being detected which results in plate solve failure and then ASIair fails to resume imaging. Multiple times now I wake up in the morning to find my imaging session stalled at the meridian and the majority of the night was lost. The resolution for this is to allow us to designate a specific filter for plate solving. Anytime a plate solve is needed the filter wheel should change to the designated filter (in my case the L filter which is position 1), then autorun should resume including returning to the designated narrowband filter for continued imaging . Allowing us to designate a plate solve filter would greatly reduce people from having this issue.
  2. I’ve found that the ASIair has a bug that after meridian flip, it appears to change the home position and all goto is broken. If I setup my system at the beginning of the night, set the home position and then using the ASIair App do a return to home… it goes to the correct location at ra/dec. After the meridian flip, the home position changes to something very wrong, it’s like it’s in another hemisphere. after the flip completes, if I cancel the imaging session, then from within the ASIair app tell the mount to go home, it now turns RA all the way west, then Dec points the scope through the ground… it’s like it thinks I switched from the northerm hemisphere to southern hemisphere of earth. This has to be a bug with the ASIair app… the home position should never change onces it set on the mount. It isn’t just home that’s wrong, now all goto functionality is trying to view objects in the ground. I think somehow you have an error in your code that after a meridian flip the RA & Dec numbers are also flipped, so the mount runs backwards, if I tell it to slew east, it actually slews west. Doing a meridian flip back doesn’t resolve the issue. The only fix I could find was to reboot the ASIair, reboot my mount and run my mount alignment again, then run ASIair’s polar alignment again.

Please look into these issues. My gear is a Celestron CGX mount connected to a Starsense hand controller. I also tried the Nextstar hand controller and had the same issues.

    Kring 1. Thank you for the feedback. Will consider an improvement? Apart from designate a filter to do plate solve, how about longer the exp time when plate solving with narrowband filters?
    And please submit the feedback and log in when you met this problem, our devs will check how much the exp time is when you using narrowband filters.

    1. Can you submit the feedback in ASIAIR App when you met this problem? Will conveyed to our devs.

      Thanks for quick reply! also forgot to mention how much I love my suite of ASI products (1600mm, filter wheel, 2x EAF, 2x ASIAIR Pro, 174mm, 290mm.. so you have a loyal customer here!

      I'm not sure about the exposure length is needed, might be nice to control that but I don't think it would be in place of designating a specific plate-solve-filter such as "L". I think the biggest issue is that at a 3nm or 6nm wavelength of such a narrow band filter, all the fainter stars never show up. I do 300sec subs and have 2800mm focal length (Celestron C11) so already a small sky to plate-solve, but it does work perfectly with Luminance or CLS filters. If I am pointed at a DSO there might only be 15-40 stars in my camera's view (lucky if I get 2 stars in OAG guide cam). So with such a limited and narrow sky view to start, then when a 6nm OIII filter is applied, it drops to only 2-3 visible stars over the 300sec sub. increasing the sub to 600sec is probably not good and is a lot of time, so I think the best way to solve is just switch to the right filter... where only a 5 or 10 sec sub can normally achieve a successful plate-solve.

      I did submit two feedbacks via the ASIair app when it occurred, hopefully you can locate based on my email address. I know how important getting the feedback and logs are to the development team. I will keep sending those in!

        24 days later

        @asiair@zwo#45211

        Sure, going to write it separated out so it doesnt get picked up by scanners

        ct
        orri
        llo
        @gmail
        .com

        a month later

        Hello!

        I’m struggling with Meridian flip as well. Did you make any progress?

        Thanks!

          Desmond Hello!

          I’m struggling with Meridian flip as well. Did you make any progress?

          Thanks!

          The problem of Meridian flip in CGX mount has been fixed. You can try our upcoming version 1.6. If it still can't be solved, submit the log and leave your email address. We will solve it as soon as possible.

            a month later

            I have yet to perform a meridian flip with the CGX L. Can anyone confirm that the problem has been fixed?!

            3 months later
            autorun-log-2021-09-02-235158.txt
            56kB

            n i c l a s k 4 7 @gmail.com
            Hey, I got the same problem as written above with my Skywatcher HEQ-5. The problem is exactly as written above. I thought I was going insane.
            Hoping for a fix thank you!

              ancientcolors Hey, I got the same problem as written above with my Skywatcher HEQ-5. The problem is exactly as written above. I thought I was going insane.

              Looking at your log, it appears that you may not have enough exposure time/gain, or more likely, you are out of focus.

              2021/09/03 02:55:39 Plate Solve
              2021/09/03 02:55:42 [AutoCenter|End] Plate Solve failed, Star number = 22
              2021/09/03 02:55:43 [AutoCenter|Begin] Auto-Center 10#
              2021/09/03 02:55:43 Mount slews to target position: RA:12h4m33s DEC:+67°22'18"
              2021/09/03 02:55:54 Exposure 20.0s
              2021/09/03 02:56:15 Plate Solve
              2021/09/03 02:56:19 [AutoCenter|End] Plate Solve failed, Star number = 17

              Notice where it says Star number = 17 and 22? I think they mean "number of stars = 17." (or 22) If so, that is an insufficient number for a reliable plate solve.

              However, since the exposure time is well over 10 seconds, I suspect that your problem stems from either bad focusing, presence of large amounts of coma, a field that is very far from flatness, etc, and not stemming from insufficient exposure time.

              The stars need to be focused to pinpoints across the entire plate, before attempting an auto meridian flip.

              Clouds or really poor transparency could explain it too, but I presume you have already checked for that.

              Chen

              Edit: make sure that you have previously performed a plate solve from the Preview window, to get an accurate focal length for your optical train.

                5 months later

                I have the exact same issue with a CEM25. Has a solution to the problem been posted? My scope is well focused and does not have issues.

                  sanjiv Has a solution to the problem been posted?

                  ASIAIR Beta v1.9 (Build 3) was posted to iOS TestFlight a day ago. In the "What to Test" notes, it says "fix the bug of AMF," with no further details. I assume "AMF" refers to Auto Meridian Flip.

                  You can try it to see if it addresses your particular problem.

                  Be sure that you have a backup copy of the Firmware before updating. That makes it easy to revert back to the most recent non-Beta version (i.e., v1.8.3).

                  Chen

                    can you send me an invitation code for TestFlight. Thanks

                    sanjiv Really ? mine flips fine. Check meridian settings in your hc

                      Hello everyone, I have the same problem with gem45 mount. Until two months ago he performed the meridian flip without problems, now he does not perform it with the same settings. Ps: does anyone know if in the hand controller the "meridian treatment" and "set behavior" should be set to Yes? he shouldn't do it anyway asiair pro '
                      Thank you so much for the answers ...
                      George

                      • w7ay replied to this.

                        albertini376 the hand controller the "meridian treatment"

                        George,

                        The choreography for Auto Meridian flip is this: (remember that ASIAIR really does not perform the flip, it simply sends a GOTO command to the mount at the right time to the mount, so that the mount performs the flip)

                        1) ASIAIR stops the mount from tracking after doing one plate solve. This time is set in "Stop tracking x mins before meridian" in the Meridian Flip Settings menu of Mount Settings.

                        2) ASIAIR waits for the object to drift past the meridian.

                        3) At the time "Do AMF x min after Meridian," ASIAIR sends a GOTO command to the mount.

                        If the mount thinks that the target has indeed moved past the Meridian, the GOTO will cause the mount to perform a Meridian Flip. Otherwise the mount will not move across the Meridian.

                        4) ASIAIR confirms that Median Flip has occurred by taking another plate.

                        If the last plate show that a Meridian Flip did not happen, ASIAIR will repeat step (4) every 1 minute until the flip finally happens.

                        As you can see, there is nothing "automatic" about it. It is just based on timing.

                        As such, you must not set the hand controller Meridian Limit to stop tracking before time (1) above. Doing so will cause the first plate solve to fail, i.e., produce streaks instead of stars. This is pretty much the only critical thing that you need to set in the hand controller.

                        Your mount must also be aligned to the sky for this timing to be perfect. With mounts that have no encoders, this needs to be done by using stars (star alignment). With mounts that have encoders, you simply need to make sure that the mount is perfectly level and had been homed to the mount's index mark.

                        Remember too that ASIAIR depends on the plate solve before and the plate solve after the Meridian flip. Other programs use better methods (e.g., checking the pier side flag in the mount) to detect the flip. On the ASIAIR, you must make sure that the exposure time is set so that the ASIAIR is able to plate solve.

                        If ASIAIR cannot plate solve, it will not even do step (3) and (4), and because ZWO does not want to confuse the "Simple as 1,2,3" customers, ASIAIR does not warn you that Meridian Flip will not occur because it cannot do a plate solve! The mount just sits there forever. You just need to check the ASIAIR Log file to see if the plate solve had indeed failed.

                        Chen

                            w7ay,
                            Thank you so much Chen for the reply.
                            I'll try again, but I think my settings still follow your great advice:

                            Gem45:
                            DST = Off
                            Meridian treatment = STOP
                            Degress before / after meridian = 0

                            Asiair:
                            Do AMF x min after meridian = 4min
                            Stop traking x mins before meridian = 4
                            Exp time 10 sec (even though I'm currently using Broadband filter - LPRO).
                            New plate solving algorithm= NO

                            Last night my target was M78... and on the plate solve for the meridian flip the stars were more than 100 and it was not performing the meridian.
                            I also think my guide was good, the overall error was about 0.70 and the polar alignment (currently I use "all sky polar align" because I look south) I think it was pretty good
                            Until a few months ago he always performed it without problems ...

                            Giorgio

                            • w7ay replied to this.

                                albertini376 Last night my target was M78... and on the plate solve for the meridian flip the stars were more than 100 and it was not performing the meridian.

                                Did the ASIAIR stop tracking before the mount thinks it reaches zero hour angle? (zero hour angle is the physical position of them mount where it thinks it has reached Meridian).

                                Or, did the mount Stop (since you set it up that way) before ASIAIR thinks it is 4 minutes before meridian?

                                Remember that stars travel at sidereal rate across the sky, or about 15 degrees per 60 minutes of time, or 1 degree per 4 minutes.

                                If you mount is not east-west aligned to better than 1 degree, then the 4 minutes that you set is not sufficient. The misalignment can be caused by bad polar alignment, bad star alignment, or the mount not being east-west level to snaller than one degree.

                                You can check the last frame taken by ASAIIR before it reaches the Meridian flip. See if there is any hint of streaking. If there is, your mount has definitely reach the "Meridian treatment" and the plate solve will fail because stars are not pinpoints.

                                If you think the OTA and instrumentation will come to no harm if it is allowed to keep moving a few degrees past the Meridain, tell you mount not to stop at the Meridian. Let ASIAIR stop the tracking.

                                If you can't precisly align the mount's coordinate system to the stars' coordinate system, you can manually pier flip the mount; don't use the "auto" Meridiann flip in ASIAIR.

                                Chen

                                    w7ay
                                    Thank you so much Chen,
                                    I'll do as you suggested, I'll try to set the GEM45 mount like this:
                                    "degress after meridian" = + 3.

                                    and Asiair:
                                    Stop traking x mins before = 4min
                                    do AMF x min after meridian = 4 min.

                                    Do you think it will be okay?
                                    Thank you very much again for your always complete and accurate explanations.
                                    George