Duplicate message to one posted on Losmandy Group.
I am trying to understand when Meridian Flips are allowed as my attempt to do a manual flip are not working as expected.
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---- How I do the Flip Manually
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I have been testing some dome behavior and am trying to manually initiate MF operations. On Gemini L4, I recall there being a quick menu to do a MF. On Gemini II I am resorting to Goto > Coordinate Input, Enable Flip, and leave current coordinates in place. There is also a menu option in the ASCOM HC, Funcs > Perform Meridian Flip.
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---- My Configuration
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I have my limits set as follows:
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Eastern Safety Limit 99:10 (deg:min)?
This corresponds to an Hour Angle of -00:36:34 hr:min:sec
So a MF request from WEST to EAST will not be allowed if target HA < -00:36:34, right?
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Western Safety Limit 101:30
This should correspond to an Hour Angle of +00:45:43 hr:min:sec
So, 45 minutes after crossing the Meridian the mount should stop tracking
Also, a MF from EAST to WEST will not be allowed if target HA > +00:45:43
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Western Goto Limit 11:00
This corresponds to an absolute goto limit of 101:30 - 11:00 = 90:30 deg:min or an Hour Angle of +00:01:59.67 hr:min:sec
I set this conservative value to allow NINA to make a MF 2 min after the Meridian per some comments made by Jim Waters.
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---- My Experiment
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If my mount is on the WEST and pointing at HA = -01:15:00, it is too early to make a MF to the EAST. This makes sense because it would violate the Eastern Limit which only allows HA to slew 36min prior to the Meridian.
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If my mount is on the WEST at HA = 00:01:07, which happens to be within the Western Goto Limit, I am able to make a MF. No issues here.
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However if the mount is on the WEST and tracks further to HA = +00:35:00, I am unable to make a MF. This does not make sense to me as a flip would not violate the ESL and, since I am getting near the western limit, a MF would be a really good thing to do now! Why does the Western Goto Limit have anything to do with *preventing* a flip back to the EAST? I thought it was the furthest west you could go before a GOTO would *force* you back to the EAST.
Can anyone point me at a specification for Gemini II of the conditions under which the HC or ASCOM UI will accept a flip that I explicitly requested?
Once the Western Safety Limit is violated ... beeping ensues ... how do I get back on target if it won't do a goto?
Edward Plumer
Sonny Edmonds