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    Re: Using sun compass for calibrating boat compass
    From: Bill B
    Date: 2014 Jun 19, 16:00 -0400

    On 5/8/2014 4:01 PM, Greg Rudzinski wrote:
    > If an azimuth were taken at the same time as a prime vertical
    > observation then the assumed longitude could be replaced by that of the
    > reduced LOP. Meridian angle is then improved so that a more exact
    > calculated azimuth can be determined by formula:
    > Z = (Cos d) (Sin t) / (Cos Ho)
    Thank you. Played with the formula you provided above with the azimuth a
    few degrees off prime vertical, as well as spot on. Z would inevitably
    be a value a tad over or under 1. That caused me to conjecture that I
    wanted the sine or cosine of Z. For values over 1 I used the inverse.
    That seemed to agree with standard calculations of azimuth for bodies a
    few degrees off the prime vertical if I added or subtracted the cosine
    angle from 90 or 270. It seemed to fall short if the body was on the
    prime vertical. What am I missing?
    Bill B

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