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    Re: Direct Sight Reduction
    From: Charles P Cohen
    Date: 1996 Aug 23, 21:52 EDT

    >They claim that you can get an accurate fix from two sun
    >sights taken 5 minutes apart. Ocean Navigator's tests confirmed that
    >claim. Applying the method to stars, you would enter two star sights
    >taken a few minutes apart and get out your lat/lon at the time of the
    >second sight, without any need to adjust for the difference in time
    >between the two sights.
    I can believe the two-star-sight fix.  Alfonso Gonzalez had a Lotus 1-2-3
    spreadsheet which would do a "direct" (iterative) solution without plotting.
    Two sights on the sun, 5 minutes apart, gives you two circles of position
    which intersect at a _very_ acute angle.  Small errors of observed altitude
    result in _large_ errors of position in the direction at right angles to the
    It's worth the price of the magazine to find out how they worked-around that
    problem.  Thanks for the note.
                  Charles P. Cohen <cpcohen@XXX.XXX>
                  Cyborg Consultants
                  Toronto, ON, Canada
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