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    Your paper in JoN.
    From: George Huxtable
    Date: 2008 Apr 7, 17:25 +0100

    Dear Andres,
    
    Pleased to see your paper in Jounal of Navigation.
    
    Coming from an earlier generation, I didn't really take in vector
    mathematics as applied to such problems. So much of your paper went over my
    head.
    
    What I want to ask about are your words in 2.3 about correcting for the
    motion of an observer.
    
    An observer who has measured the altitude of a star to be, say 30 deg, knows
    that his locus is on a circle radius 60 deg centred at the GP of the star,
    (say, at dec = 0, GHA = 0, as in the example in paragraph 4 of my paper in
    JoN, 59, No3, pages 521-524, which I think you have). And then the  observer
    moves a known distance, say 60 miles North. His new locus is a closed
    figure, somewhat egg-shaped, but NOT a circle any longer. Does your
    algorithm in A2 find the crossings of that non-circle with another circle
    centred on another star (say, at dec = 1deg N, GHA = 45 deg W, seen at 45
    deg alt, as in that example).? What result does it give?
    
    Yours, George.
    
    contact George Huxtable at george@huxtable.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    
    
    
    
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