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    Re: query
    From: Dan Allen
    Date: 2002 Aug 21, 10:58 -0700

    On Wednesday, August 21, 2002, at 10:34 AM, 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.
    
    Check out http://williams.best.vwh.net/avform.htm
    
    which has this:
    
    Lat/lon given radial and distance
    
    A point {lat,lon} is a distance d out on the tc radial from point 1 if:
    
          lat=asin(sin(lat1)*cos(d)+cos(lat1)*sin(d)*cos(tc))
          IF (cos(lat)=0)
             lon=lon1      // endpoint a pole
          ELSE
             lon=mod(lon1-asin(sin(tc)*sin(d)/cos(lat))+pi,2*pi)-pi
          ENDIF
    
    This algorithm is limited to distances such that dlon 
       
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