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SkySafari 6 Pro (Needs Further Testing) | SkyWatcher Lunar Tracking Drifts (Solution: Resolved, Read On!)

I finally had a nice - but cold - night observing the Moon with SS6 and SkyFi. I had a terrific time, but it also showed a number of problems with SS6. Perhaps you are acquainted with the "Lunar 100", which is a baedeker of things you should see on the Moon. I have made an observing list with these objects - or most of them, because there are a couple that are not in the SS6 database, and a couple that are too general to be in the database - and I highlighted this list. It turned out that as the Moon is moving across the sky, the highlights stay where they were, so after an hour or so, you have the Moon in one place, and the 90 or so highlights bunched in the black sky somewhere else!

I set my Skywatcher telescope to "Lunar Tracking", and the telescope control worked like a charm, centering the desired feature even when it was just a little distance from the previous feature - except for one problem: the alignment drifted all the time, and I believe it is because SS6 is not aware of the Lunar Tracking but assumes Sidereal Tracking. I fixed this pressing Align before each GoTo next object.

Another problem was that whenever I left SkySafari to look at another app, such as the PDF I have with the description of the Lunar 100, SkySafari "went wild" when I returned, and moved some distance away from the Moon. I could freeze the movement by tapping the screen while it happened. Otherwise I would have to zoom out to find the Moon and zoom back in again. I think I could have pressed Align to cause it to move back to the selected feature, but I did not think of it, so I did not try.

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    Bill Tschumy

    Steen,

    Thanks for the report.  I will ask Tim about the highlighted lunar features not being updated correctly.  I agree this looks like a bug.

    When you say the alignment "drifted", could you explain how that was manifested?  What did you see happening?

    If you could try to reproduce your 3rd problem and let me know the steps to reproduce, I'd appreciate it.  We haven't seen this before.

     

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    Steenkh

    By "drifting" (sorry if this was not a good English term) I mean that the center of the screen with the cross hairs of the telescope slowly moved away from where the telescope was pointing. The selected feature stayed selected, which was why I could move the cross hairs and the center back by pressing Align. This movement does not happen when pointing at some star and using Sidereal Tracking.

    It is my guess that SkySafari is locked at some place in the sky, and it is the Moon that is moving away from that spot - but I could be wrong, because the movement is very noticeable, and seems to me to a bit fast, but that is just my subjective feeling.

    The third bug appeared in this way: I am using an iPad, and SkySafari is connected to the telescope. The selected object was some feature on the Moon. I swiped to the left using three fingers in order to go to the GoodReader app where I could read my Lunar 100 pdf file. When I swiped back, the bug happened. I believe that the bug also appeared when I used the Home button to visit another app, but I am no longer sure.

  • 0
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    Bill Tschumy

    Steen,

    We have fixed the bug where the position of highlighted Moon features weren't updating properly as time passed.

    The drift problem is interesting.  This almost seems like it must b a bug in the SkyWatcher firmware.  Every 1/4 of a second we are asking the mount where it is pointed.  If the scope location is moving that can only be because the mount is returning the wrong location.  I wonder if they are not updating something correctly internally when you are doing lunar tracking rather than sidereal.

    To be honest I have never used this swipe gesture to change apps.  Looks like it is 4 fingers, not 3 (unless I'm confused about what this is).  I just tried this a couple of times when connected to a Celestron mount.  I didn't see any problems.  Could you try to reproduce this please?

  • 0
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    Steenkh

    I am not where my telescope is for the rest of the week, but I tried the demo interface and connected SS6. Again I used my observing list of Moon features, and I selected a random object and pressed Center and GoTo.

    I noticed that the crosshairs of the telescope moved slowly away from the selected crater so bug #2 is not dependent on a Skywatcher telescope.

    Then I swiped to another app - with four fingers as you noted - and back again. This time it was clear that the connection to the telescope was lost and the view moved to another place. The connection was quickly reestablished, but the view did not move back to the Moon. This could be what happened under real circumstances, but I did not notice that the connection was temporarily broken, so it could be bug #3. The same thing happens when moving to another app using the Home button.

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    Bill Tschumy

    The Demo scope is assumed to track at sidereal rate so it is not surprising that the Moon would drift.  There is no way to set the Demo scope to track at lunar rate.

    Tim set up his Orion mount (same as SkyWatcher) and he doesn't think the lunar tracking rate is working at all with it.  So it may have been tracking at sidereal rate even though you had it set to lunar.  If you left a crater centered in the field of view for 15 minutes, did it stay centered?  That would be the real test.

    We close down the connection to the mount when the app is in the background.  We reconnect and center on the scope's location.  I am unable to explain how you end up with it not re-centering on the scope after it reconnects.  Do you see that with the Demo scope as well?

     

  • 0
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    Steenkh

    I cannot say for sure that lunar tracking works with the Skywatcher telescope. It has always been my assumption that it does. I believe that three years ago when I had just got the telescope, I once left the telescope pointed at the Moon for a couple of hours while I was waiting for the sky to get darker, and I was very satisfied that it worked. But that is a long time ago and I no longer remember specifically having put the telescope in lunar tracking mode. But how else could it work for that long? I  am sure I used my 24mm eyepiece, so the full Moon looks as if it fills the entire image.

    This weekend I only left the telescope at the same spot for about five minutes, but at a much higher magnification (375x), but I did not notice anything special about the tracking, whereas it was obvious with SS6.

    The weather forecast for next weekend is overcast, so it could take a long time before I can make a comprehensive test.

    The demo scope is probably not the best test for bug #3, because it loses the location also when disconnected. I am sorry I did not make any serious testing of all these things, but the temperature was -7°C, my fingers felt as if they were made of ice, and there was a cold wind breathing down my neck (I could not use a hood because it interfered with my viewing). Next time the weather will hopefully be more clement, but that could be as late as April.

  • 0
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    Steenkh

    The weather has not permitted me to take the telescope out for most of the winter, and now it is spring, and the nights are so bright that it is hardly worthwhile to do it any more. While waiting for the Moon to make an appearance on a clear sky, I have tested a little bit in daylight. I pretended that it was dark, let the telescope pick suitable stars, and accepted the alignment as fine. Then I moved to Venus and started testing, or rather demonstrating, the issue with 4-finger swiping.

    I produced a small video that you can watch on <https://www.dropbox.com/s/p3t9kg5icdd3oiu/SkyFi%20Swipe%20issue.MOV?dl=0>. You can see that I had centered on Venus, then I swipe away, swipe back, and SkyFi thinks that the telescope has moved away from Venus. Then I realign on Venus, do the same thing, and the same thing happens again.

    My first claim that SF6 goes wild, was probably caused by a higher zoom factor. On this video, you can see exactly how far the alignment moves.

    Now, I can imagine that SF6 is not designed with swiping in mind, but at the very least, the behaviour is curious, and if we are lucky, the correction may be easy. If not,we just have to accept that SF6 does not like swiping.

    But another thing also happens. When swiping, I could hear that the motors of the telescope stopped briefly, and then started again, so SF6 sends some command to the telescope. How much this brief stopping of the motors meant, I cannot tell, because I could not actually see Venus in the telescope.

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    Bill Tschumy

    I'm sure this has nothing to do with swiping.  I expect you'd get the exact same behavior if you put the app in the background and then came back to it.  I'm curious if the amount of the jump is dependent on how long you keep the app in the background?  In your video you seems to have the same (or similar) background time and thus the jump was similar.  Could you test this please?

    It is interesting that you hear the motors stop briefly and then restart.  I suppose the jump you are seeing could be due to the mount stopping tracking for a few seconds and then restarting.  The object would drift during this non-tracking period.  Looking at the code, we don't send any commands to the SkyWatcher scope when we close the connection so I don't know why this would be.

    Perhaps you could capture a scope log file and send it to me (bill@simcur.com) and I can see what happens when we close the connection.  I don't have a SkyWatcher scope with me at the moment so I can't do the test myself.  It instructions for capturing a scope log file are in the Help > Settings Help > Scope Setup Help (near the bottom of the page).

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    Steenkh

    I have done the same test again, and I can tell you that the jump is not dependent on how long I leave SF6 in the background.

    I also generated a log file - or rather four log files, because it seems that a new log file is generated each time SF6 is coming back from the background. I am sending these logs to you.

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    Steenkh
    Hello Bill,
     
    You asked me if I would beta test so that I could test the fix you work on. I said yes, and my AppleID address is steenkh@joste.dk, but I have not heard from you about beta testing again.
     
    You are now beta testing a new feature. Should I register for this beta testing, and then test the fix for my own problem with it? For yet another month I cannot test the new AR feature for you because there are no stars here until after midnight, and I have to sleep before that.
  • 0
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    Bill Tschumy

    Let me see if the possible fix is in the AR beta. I think the answer is yes, but I'm not certain.

     

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    Steenkh

    I  got the new AR version today, and as luck would have it, I visited my telescope, so I could test immediately to see if this problem has changed. Alas, it has not. I hope the fix was not included in this build, because if it was, it did not work.

    One thing has changed though: The short break in the motor noise has disappeared. I tried swiping, and pressing the Home button, but the motors whirr quietly without interruption.

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    Steenkh

    Update: There are good news! I checked the newest version and this problem has completely gone away. So it was not a firmware problem after all.

     

    My version is 6.3.0.0.

  • 0
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    Bill Tschumy

    Steen,

    Thanks for the news.  Glad it is working.

    Bill

  • 0
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    Steenkh

    Maybe you should change the title of the thread to "Resolved: "

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