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    Re: Ratio of variances
    From: Greg Rudzinski
    Date: 2018 Nov 2, 08:30 -0700

    Bill,

    With experience you can call the shots which means that a navigator can give a weighted percentage to the quality of the observation. The horizon sharpness, late twilight, cloulds, rough weather, stability of vessel,  optics power/clarity, and sight reduction method used are some of the factors to consider when putting a confidence percentage on an observation. Sometimes all that is available will be two low confidence sights separated by a narrow azimuth cut.  The fix error circle would then be large (lets say >6nm radius as an example). An example of high confidence would be four observations seperated by 90° using an artificial mercury horizon all at the same altitude of lets say 25°. The error circle would be very small (< 0.5nm).

    Greg Rudzinski

       
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