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    Re: Meridional Distances
    From: Paul Hirose
    Date: 2002 Sep 19, 16:21 -0700

    Vic Fraenckel wrote:
    > My routines give the azimuth (referenced to true north) of the second point
    > from the first point (and the azimuth from the second point to the first
    > point - NOT recipricals on an ellipse).
    Yes, that's what I figured you meant. I don't even know what a
    reciprocal on an ellipse is. My point was that the Mercator methods
    yield a rhumb line, which is easier to follow. You simply keep a
    constant heading throughout the voyage. (I'm ignoring variation etc.
    for simplicity.)
    On the other hand, computing the azimuth from Point A to Point B
    yields the initial heading for a great circle course. However, if the
    vessel stays on that heading it will miss Point B. The miss may be
    trivial or huge, depending on distance and the lat/lon of the points.
    The rhumb line and great circle methods both have their place in the
    navigator's arsenal.

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