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    Re: Data from three lunars, with some comments
    From: Herbert Prinz
    Date: 2003 Jan 15, 18:34 +0000

    Fred Hebard wrote:
    > [...]  The apparent distance was cleared for the effects of
    > refraction and parallax by Young's method, as laid out by George
    > Huxtable last year (I don't think George's implementation of Young's
    > method corrects for anything else). [...]
    Hello Fred,
    For the sake of clarity, it should be said that "Young's method" as described by
    George Huxtable (and Cotter) is just a rigorous formula for obtaining D from d,
    h_sun, h_moon, H_sun and H_moon. As such, it does not correct for anything per se,
    it only puts to work exactly those corrections that you have made in establishing
    its input parameters. It is largely a matter of taste how much effort you want to
    put into clearing those parameters before putting them into Young's (or anybody
    else's) formula.
    With approximative clearing methods, it hardly makes sense to apply corrections
    that are smaller than the inherent precision of the formula. But since Young's
    formula is a strict one, there is no limit to the madness: You could consider
    corrections for augmentation of SD moon incl. its correction for latitude, HP of
    both bodies, corrections of HP moon for latitude; corrections for refractional
    contraction of vertical diameters to apply to apparent altitudes and likewise
    contraction of inclined semi diameters to apply to the apparent distance. Even with
    all those, the true distance obtained will still not be the true geocentric
    distance as tabulated in the almanacs, but that reduced to a point which is the
    intersection of the local vertical with the rotation axis of the earth.
    Looking at your data, it appears that most of the observed distances suffer from
    transcription errors.
    For moon/Jupiter lines 4  to the last: Read 52� instead of  53�.
    For moon/Aldebaran, from the 2nd line on: Read 68� instead of  69�.
    For moon/Sun, for all seven obs. Dist. read 103� instead of  104�.
    Best regards and thanks for sharing your experience.
    Herbert Prinz

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