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Gemini Goto and epoch

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#1 lineman_16735

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Posted 23 August 2009 - 11:29 AM

I'm having some trouble getting my Gemini system and The Sky 6 Pro to play nicely together. Goto's from within the Sky 6 do not send Gemini to the proper location. Goto's from the hand controller do send Gemini to the proper location. This is frustrating to say the least. Is the Sky set to J2000? The Gemini is set to J2000 and I have a very good model in place. I know it is something simple but can't fiqure it out. Any ideas?

#2 gnowellsct

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Posted 23 August 2009 - 09:58 PM

If you don't get your answer here try the Losmandy group on Yahoo. Many thousands of losmandy users. good luck Greg N

#3 Charlie Hein

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Posted 24 August 2009 - 05:35 AM

I'm having some trouble getting my Gemini system and The Sky 6 Pro to play nicely together. Goto's from within the Sky 6 do not send Gemini to the proper location. Goto's from the hand controller do send Gemini to the proper location. This is frustrating to say the least. Is the Sky set to J2000? The Gemini is set to J2000 and I have a very good model in place. I know it is something simple but can't fiqure it out. Any ideas?


Did you try doing a go-to from TheSky, centering manually then synching? I don't think that TheSky makes use of your pointing model in the Gemini, but you might at least get them to agree with each other.

#4 lineman_16735

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Posted 24 August 2009 - 07:56 AM

Yes I have Charlie. Once I do what you suggest the crosshairs in the sky are not on the object I just synced on. For instance:
Goto Vega with The Sky
Vega may or may not be on the chip. Then I select Vega in the sky and center it on the chip and sync. The crosshairs in the sky move about 10 arcminutes or so off of Vega. Any Goto's I do with the hand controller are fine. My polar alignment is very good as well. Another point to make is that after I sync on Vega and the crosshairs move in The Sky. A goto even a very close star to Vega is way off.
Center Vega chose vega in The Sky and sync. The cross hairs then leave Vega and move about

#5 Charlie Hein

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Posted 24 August 2009 - 09:22 AM

Strange. I know that this is probably a dumb question but are you certain that the mount and PC are synched in time and location? This could cause what you're seeing too.

I was looking at the help file for TheSky to see how they figure the Epoch but this documentation seems somewhat vague and I had to head to work before I could do a decent investigation. If I had to guess based on what I've read so far it uses 2000.0 as the Epoch but can be corrected for precession at need.

#6 lineman_16735

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Posted 24 August 2009 - 09:36 AM

Not a dumb question Charlie, but I did check the time/date in the Gemini and The Sky. Perhaps it is a bug in the version of Gemini I am running L4 V1.01? The Sky help files are tough to follow for me.

#7 Charlie Hein

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Posted 24 August 2009 - 09:52 AM

I know what you mean. I downloaded a copy of the .pdf manual and had a brief look around. The coordinates in most of TheSky6’s databases are for Epoch 2000.0 – the position of objects at 12:00 hours UTC on January 1, 2000. This doesn't *quite* equate to J2000 which per Wikipedia is actually January 1, 2000, 11:58:55.816 UTC. I don't believe that this is enough of an error to account for what you're seeing in the Virtual Sky, but it is there.

I want to try this out on my mount and laptop - unfortunately the sky doesn't look very good for the next couple of days but as soon as I can get a chance to check this out I will. I don't recall synch not working the last time I tried so I do want to verify this. If I'm working well thenm maybe we can match settings to see if this fixes you up.

#8 f29pc

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Posted 24 August 2009 - 10:22 AM

What driver are you using to connect the sky to the Gemini?

#9 Charlie Hein

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Posted 24 August 2009 - 11:18 AM

Good question - I'm using the ASCOM driver.

#10 f29pc

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Posted 24 August 2009 - 12:25 PM

I have used the Sky6 with the ASCOM driver, and had the Gemini set to Jnow, and it worked fine with V. 1.04. If you use the Telescope API and the Gemini controller from Ajaiseghal, be sure to un check the "sync affects model" or it will change the model in the gemini. Also there is a file in the Gemini user group that is called "Fix the sky6 and Gemini.exe", you might try that.
Paul

#11 lineman_16735

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Posted 24 August 2009 - 03:54 PM

Thanks Charlie and Paul. I am using the Sky's native driver. I will try it with the Gemini driver. I'll join the Gemini group as well.






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