A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2018 Nov 2, 08:30 -0700
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).