Re: PemPro Polar Alignment differs East to West

Joe Zeglinski

    I think I have found the solution to solving the east-west PemPro curve difference. Simple really.
    Atmospheric refraction is ALREADY being taken into account by Ray’s PemPro algorithm, so it really should not be an issue here. However, if there is even some slight variation, during the target run, greater in the western part of the sky, one could very easily produce an “Averaged East-West Pier side” curve by the following procedure:
    Rather than settling on doing a raw data sample run for say 6 cycles – Either on one side of the pier, or on the flip side - (and ... further, assuming there are no obstructions for a “reasonable”  span on the prime meridian) – lets start pointing toward the eastern sky, by HALF the suggested (or chosen) offset angle, and let PemPro run past the meridian ending at the same offset half-angle on the western sky, to finish its LAST 3 cycles.
    Doing PemPro this way, the target has the SAME amount of EVER decreasing & then increasing atmospheric refraction, for the same number of cycles, split between the two sides of the pier.
    What might make this easier, would be if PemPro could make a note of the “actual” pre-meridian offset angle – since the user may have caused some angle delay in preparation of the run, such as the required Calibration wizardry,  and run the other HALF of the cycles until the same post-meridian angle is reached. At that point,  PemPro automatically ends itself,  in preparation for the resulting raw data curve  analysis phase.
    The option screen may need to be changed from choosing the number of cycles, or duration – to time or angle ahead and after crossing the meridian.
    I think this would be ideal.
Joe Z.

Join to automatically receive all group messages.