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    Re: Submarine celestial through periscope
    From: Andrés Ruiz
    Date: 2023 Mar 13, 09:49 +0100

    Another example: 3 LoPsthat almost form an equilateral triangle.

    Polar sky.png
    Hc Zn.png
    Sights.png
    Plot.png

    Map.png
    EoC.png


    Comparison table between the two examples:

     

    Orion fix

    3 sights - Equilateral triangle

    EoC

     

    Prob = 0.9500

    k = 2.4477

    theta = 6.5112

    a = 0.0067

    b = 0.0630

    Prob = 0.9500

    k = 2.4477

    theta = -0.0120

    a = 0.0058

    b = 0.0063

    DOP

    5.50 Moderate

    1.16 Excellent

    Z factor

    0.99

    0.04



    Re: Submarine celestial through periscope
    From: David Pike
    Date: 2023 Mar 11, 03:40 -0800
    ... GNSS is range spheres and receiver clock correction, whereas intercept method celestial is intercepts and azimuths. 

     Intercept method is based on Marcq Saint Hilaire line of position, is a linearization of the general problem of celestial navigation, in the neighborhood of the position.

    CoP cones.g295content.pdf.png

    The Circle of Equal Altitude is the intersection of a cone with the apex on the star and the Earth ( sphere or ellipsoid)


    References:

    navlist.net/cones/

    Dilution of precision (navigation) - Wikipedia

    Celestial Fix - n LoPs - by Least squares Sight Reduction algorithm. Paper & Excel https://sites.google.com/site/navigationalalgorithms/Home/papersnavigation


    Fair winds!
    --

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

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