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    Re: The Running Fix on an Ellipsoid
    From: Andrés Ruiz
    Date: 2017 Feb 6, 09:36 +0100
    An example of thorical CoP with their GP on the equator:

    Imágenes integradas 1

    sin H = sin B sin Dec + cos B cos Dec cos LHA
    This equation could be plotted on a Mercator chart, a sphere or a ellipsoid, the shape changes, but the points will be the same.

    (Input file for PlotCoPonMap.exe is provided)

    2017-02-05 20:48 GMT+01:00 Robin Stuart <NoReply_Stuart@fer3.com>:


    You wrote: The only with i do not agree is the claim that: "On the sphere, points on the LoP all lie the same geodesic distance from GP; however this is not true for an ellipsoid".

    Well spotted. I believe the statement to be true but you are correct "this is not the nature of the CoP." or if I may paraphrase "geodesic distances along the surface are not relevant to the problem at hand". It's really an aside or Note to Self. It arose as I contemplated the fact that if the equation ot the LoP or curve constant altitude are the same on the sphere and ellipsoid and asked myself then in what way were they different. On the sphere, because of it's constant curvature, points on the LoP lie all at the same distance from the GP. On the ellipsoid however the curvature is different in different directions and the geodesic distance to different points on the LoP will be as well. Just consider the case of a GP on the equator,



    Andrés Ruiz
    Navigational Algorithms



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