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    Current Bowditch errors
    From: Andrés Ruiz
    Date: 2008 Jul 14, 09:21 +0200
    Current Bowditch errors

    Jeremy,

    From my mail [NavList 3693]:

    Bowditch use for the calculation of the meridional parts two concepts that are based in none model:

    a = 21600.0/(2.0*PI)  is used in the spherical model of The Earth

    f  = 1.0/298.26       is used in WGS72, but this use a = 6378135.0/1852.0


    Also there is some confusion in commercial Route planners use different kind of sailings:

    -       OziExplorer – Great circle and great ellipse
    -       C-MAP - PC Planner V 11.0.0 – Middle-Latitude Sailing , wrong for long routes
    -       MapTech OffShore Navigator – Mercator sailing or loxodromic, WGS84?

    Andrés


    De: NavList@fer3.com [mailto:NavList@fer3.com] En nombre de Anabasis75@aol.com
    Enviado el: viernes, 11 de julio de 2008 17:46
    Para: NavList@fer3.com
    Asunto: [NavList 5801] Re: Noon sight for longitude

    Andrés:

    I am advised that the current Bowditch has many more errors. I quoted
    from the 1952 edition, where the limits are stated as, "for a stationary
    observer," and "if there has been no change in declination." I advise my
    students to use an older edition of Bowditch.

    Jim Wilson

    NavList 5800] Re: Noon sight for longitude

     

    -----------------------------------------------

     

    Except for some information on the electronic navigation systems, modern editions of Bowditch, starting with the 1995 edition, have been generally inferior in most respects.  My favorite edition is 1985 Vol I, 1981 edition Volume II.  One small note, the more modern Meridional parts tables are slightly different and more accurate, but I don't think it matters all that much.

     

    Jeremy


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