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    Re: Doniol for time sight reduction?
    From: Lars Bergman
    Date: 2015 May 16, 13:37 -0700

    Greg wrote: "If Lars is watching then maybe he can work up something that will look good."

    I think the following at least looks good:

    hav LHA = (hav z - N)/(1 - Q)

    where N=hav(lat-dec), P=hav(lat+dec) and Q=N+P

    z is the zenith distance 90°-altitude

    Like the azimuth formula, the division by 1-Q is the tricky part. If Q is small, then an approximation is to multiply with 1+Q instead.

    Lars, 59N 18E

     

       
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