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    Re: Azimuth Equation
    From: Bill B
    Date: 2005 Oct 19, 04:03 -0500

    > I'm using the azimuth equation out of the Nautical Almanac:
    > cos-1[(sinDec cosLat)-(cosDec cosLHA sinLat)/cosHc]
    > To find Hc: sin-1[(sinDec sinLat)+(cosDec cosLHA cos Lat)]
    > In entering the equation, if the Declination or latitude is South, or the
    > Longitude is West, the value is negative.
    If you have followed the list, you know I am far from a list guru or math
    whiz.  Using your numbers, I plugged into a TI-30XA with no problems.  I do
    not fully recognize the formulas stated as they appear on my monitor,
    especially as there are no equal (=) signs.  Probably an ID-10 T error on my
    I do recall a discussion a good while back (if I recall correctly) as to the
    merits of using tangents for azimuth when certain angles (near 0d or 90d?)
    are involved by one of the list gurus, but won't swear to that.
    I know that is not much help, but I don't have much to go on.  Perhaps it
    will jog the collective memory.

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