Use Robostar to handle Meridian Flipping?

Hello,

I know my subject title is confusing. If I select NOT to manage Meridian Flipping in Sequence setup and use Robostar as part of single star auto focusing, will Voyager treat this as similar as if Manage Meridian Flip is enabled?

In other words, while running the Sequence and both star for Robostar auto focusing and target DSO already crossed the Meridian and Manage Meridian Flipping is disabled and it’s time to run auto focus again, the mount will certainly flip because Voyager will command the mount to slew to a star that already crossed the Meridian for the purpose of running auto focus, will Voyager eventually treat this as Meridian Flipping meaning that Voyager/PHD2 will have to reaquire guide star (I use OAG) and properly resume guiding.

I hope I am making myself clear. My mount is A-P1100GTOAE and in the past I never need to do Meridian Flipping for target DSOs at the Southern sky up to south of Zenith. I don’t mind Meridian Flipping with Voyager and my goal is to get the sharpest focus.

Please let me know if you don’t understand and I will try to rephrase my original post.

Peter

If you put not manage flip in sequence voyager will not do operation for recalibrate guide or precise pointing if mount flip.

Hope this help you

Peter

Not entirely sure of what you want to achieve: do you want to avoid meridian flips and focus on same side as target?
I have an AP1100GTO and have manage meridian flip enable in Sequence and ticked the box telling Voyager that meridian flips are managed by the ASCOM driver: https://voyager.tourstar.net/index.php?title=Sequence_Configuration#Meridian_Flip_Tab

I have APCC configured for my meridian and horizon limits and image with counterweights up all the time. Voyager interacts just as expected with APCC and the latter manages flips.

Roberto

Hi Leo and Roberto,

Thank you for responding.

Generally speaking, if I can image an object all night from East to West without Meridian Flipping, that’s my preference. Probably using Voyager Local Field auto focus would be a better choice.

If the DSO is located where the scope could collide with the pier after crossing the Meridian, I would not mind having Voyager manage Meridian Flip.

My bottom line is I just prefer not to use Meridian Flipping when I can.

Here is a scenario about what I am talking about when using Voyager Robostar and whether Meridian Flip is managed or not. Let’s say that I enabled managing Meridian Flip and set to do Meridian Flip 20 minutes after the mount crosses the Meridian. Supposedly both target DSO and a star for Robostar already crossed the Meridian but still within the 20 minute time frame before Voyager manage Meridian Flipping and it’s time to run auto focus, the mount will flip and slew to the Robostar star, focus the star and slew back to target DSO, then how will Voyager manage this scenario for re-calibrate guide or precise pointing if mount flip before the 20 minute managed Meridian Flip time frame?

In other words, how will Voyager manage the Meridian Flip when the Robostar auto focus caused the Meridian Flip to happen BEFORE the 20 minute managed Meridian Flip time frame?

I hope I am making myself clear. I realized the chance of this happening is very slim but can still happen.

Thank you,
Peter

Peter

I do not set times before or after meridian for Voyager to manage the flip (in Mount Setup). I only specify that Voyager manages the flip using the ASCOM driver in Sequence (as per my link). Voyager sends GoTo commands to the mount (for focusing and targets) and APCC decides whether to flip or not (depending on limits set within it).
I also prefer not to flip, and if object is low enough, sometimes don’t have to as APCC starts CWs up deep in the Eastern horizon.

Roberto

Hello Peter,

For your info :

  • Robostar never choose a star in the other side of meridian …this to avoid Meridian flip.
  • if you manage meridian flip, in the interval of time before and after meridian setlled in Voyager focus will be not done if RoboStar and all goto are aborted. If a goto is necessary to continue the sequence will be paused until the mount exit from the interval and all restart with a flip.
  • If you not manage the pier flip if a goto generate a meridian flip in this case not recalibration or precise pointing , you can have target out of image and problem with guide.

All the best
Leo

Hi Roberto,

I was referring to setting Meridian Flip time setting in Mount Setup at:

https://voyager.tourstar.net/index.php?title=Mount_Setup

The Manage Meridian Flip settings is in Sequence window.

Peter

Hi Leo,

That’s the answer I was looking for. If your description is not in Rowland’s Wiki manual, maybe mention that.

Thanks,
Peter

Peter

I think you got what you were looking for but just in case my settings are below (screenshots). As I said, I image CWs up regularly.
Roberto

image

Thanks Roberto.

I am new to Voyager and have not yet tried first light with it. I migrated from SGP in the hopes that Voyager will do a better job auto focusing. After reading Rowland’s excellent manual, I believe I got the hang of setting up and operating Voyager. It’s really not much different than SGP, just learning different formats, that’s all.

So, what method of auto focusing are you using (Robostar or Local Field)? Any tips you can give me? I do not use APCC and I am not really interested in purchasing yet since my setup is always portable.

Peter

Hi Peter
Noted on APCC; handle the meridian with care then (as I’m sure you are).
I have used both methods. Single star is faster than local field for me - since my CCD uses a 16803 chip - and downloading even a portion of it takes some time. Both produce excellent results. I have little tilt or aberration in my full frame so the difference in eccentricity from using single versus local field is minimal. I also prefer to focus higher near the meridian and as sometimes image lower in the sky, single star is better suited than local.
Roberto

Thanks Roberto.

Peter

Hi Leo,

I have a strange idea. If I selected to Manage Meridian Flip (i.e. Flip 10 minutes after crossing the Meridian) and Robostar Auto Focus, when the DSO already crossed the Meridian but before the 10 minute deadline to flip Meridian, how about let Voyager use Local Field auto focusing until DSO passes the 10 minute Meridian Flip deadline and continue use Robostar auto focus from then on. This way auto focus will always run regardless where the mount is pointing. Maybe add a checkbox for that.

Would that work?

Thanks,
Peter

Hello Peter,

is an idea … but not all setup can run a LocalField Autofocus. Anyway with checkbox is possible to choose.
If you choose 5 in before and 5 after (default) i dont think you need to do focus for 10minutes

All the best
Leo

Hi Leo,

That’s a great idea. I missed that part.

What happens if the filter wheel changed during this 5 minutes before and 5 minutes after? When the filter changes, I need to re-focus.

Thanks,
Peter

If you need focus if is robostar focus will be bypass. But if you use flag in sequence to inject focus on meridian flip you minimize effect just for one sub (depend on your sub time)

OK, thank you.

Peter