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    Re: Position from altitude and azimuth.
    From: Andrés Ruiz
    Date: 2020 May 19, 21:14 +0200

    There is a slight misunderstanding about the nature of certain types of Lines of Position, LoPs.



    The Isoazimutal of a star is not Great Circle (GC), nor a small circle. How they look like

    The Bisertor of two Azimuths, azimuth difference, is a hyperbolic LoP.

    The circumference of equal altitude or Circle of Position, CoP, is a small circle.

    ·         If Ho = 0º The CoP becomes a GC

    ·         If Ho = 90º CoP becomes a point: the GP, illuminating pole of the observed star or substellar point.

    The LoP based on a Horizontal Angle, used in coastal navigation with a sextant, are two circles of position. And they are not a isoZ either.

     


    Several of these LoPs are plotted on a map with my CharWork application.

    See attached examples of  Horizontal Angle LoPs from http://dept.navigation.enmm.free.fr/navigation.htm (Permission allowed)

    https://sites.google.com/site/navigationalalgorithms/software/Windows


    Regards

    --

    Andrés Ruiz
    Navigational Algorithms
    http://sites.google.com/site/navigationalalgorithms/

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