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    Re: query
    From: Peter Fogg
    Date: 2002 Aug 23, 08:14 +1000

    The formula I am using at the moment goes:
    
    lat2 = lat1 + [(nm/60) x cos TC]
    
    then work out the middle latitude (ML):
    
    ML  = lat1+lat2 / 2
    
    long2 = long1 + [(nm/60) x (sinTC/cosML)]
    
    I hope you can follow my notation - '/' means 'divided by'. TC needs to
    be in
    the 0-90� range. North and East are positive values, South and West are
    negative. This formula is not especially accurate (probably doesn't need to
    be) and I shall be interested to try out the other formulas suggested.
    
    
    
    
    
    Mitch B Burrill wrote:
    
    > If I am at lat1, long1,  and go XXX nm at TC YYY,
    > What is the exact formula from spherical trigonometry to get lat2, long2 ?
    > I have looked everywhere for this, I must be doing something wrong.
    >
    > Thanks !
    >
    > Mitch Burrill
    > mburrill{at}leesburgva.org
    
    
    

       
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