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    Re: Submarine celestial through periscope
    From: Andrés Ruiz
    Date: 2023 Mar 8, 11:10 +0100
    A sense of the goodness of the distribution of the sigths is given by the EoC, Ellipse of Confidence, and by the Azimuth Factor

    /*
    THE ACCURACY OF CELESTIAL FIXES AS COMPARED TO NAVSAT POSITIONS BY LEAST SQUARES ADJUSTMENT
    H. F. Van Der Grinten
    NAVIGATION, Journal of The Institute of Navigation
    Vol. 22, No. 2, Summer 1975
    pp. 128-134.
    */


    public double AzimuthFactor(double[] z)
    {
        // Observations perfectly balanced 0 <= fabs <= 1 Observations totally imbalanced
          int n = z.Length;

          double sZn = 0;
          double cZn = 0;

          for (int i = 0; i < n; i++)
          {
              sZn += SIN(z[i]);
             cZn += COS(z[i]);
        }
          double f = sqrt(SQ(sZn) + SQ(cZn)) / (double)(n);

          return (f);
    }


    Azimuth factor.Grinten.PNG

    Re: Submarine celestial through periscope
    From: David Pike
    Date: 2023 Mar 7, 13:03 -0800
    Andrés
    Please explain what you mean by ‘azimuth factor’ in this context.  Also, are you suggesting that if you work in three dimensions rather than two, fixes are still practical even if the differences in plan-view azimuth between stars is less than 30 degrees (the RAF limit).  DaveP



    3D, 2D, ..., Sorry Dave, I don't understand what you mean

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

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