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Hey Peter,
I should have been clearer! I don't want to drift align using Jupiter, I want to drift align normally but manually calculate what the compensation adjustment should be - then use Jupiter's diameter as a visual reference to get the magnitude of adjustment correct.
So the drift alignment session might go like this.
1. Note how big Jupiter appears in my imaging camera's view finder - it fills up half the central square focusing box - so the box itself must be around 100 arc seconds corner to corner - that's my imaging guide.
2. Guide on say Rigel when its between 25 - 30 degrees elevation for 30 minutes.
3. Either using the eye piece or a before after shot not only notice the direction of the DEC drift - but measure it manually to get a magnitude number in arc seconds.
4. Plug that drift magnitude and time into the above formulea and note its magnitude of correction. Lets say it was lower mount 100 arc seconds.
5. Goto Jupiter and centre it on a corner of my imaging camera's central box.
6. Manually lower my mount 100 arc seconds by thinking of it as two Jupiter diameters.
So really the change I am suggesting to a normal drift alignment is to:
1. observe the DEC drift angle for a given time
2. manually calculate the polar correction required
3. execute the polar axes correction using Jupiter's diameter as your angular yardstick
The alternate to this is to either simply guess how much correction is required or use software like PEMPro's Polar alignment wizard (which is throwing very wierd correction numbers at me - so I want to manually confirm how much polar misalignment I may have).
So lets say I track Rigel for an hour and I measure its drifted in DEC say Half of Jupiter's diameter in my viewfinder. If I know drift is close to 25 arc seconds in 3600 seconds, the the formulea tells me the correction magnitude is ~ 96 arc seconds - or about two Jupiter diameters. I want to use Juptier as my angular measure to make the physical adjustment of my gear.
Does this make more sense?
BTW - I think my mount actually tracks planets at non sidereal rates, but that's another variable I don't want to bring into the mix.
Cheers,
Matt
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