NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Celnav article in Ocean Navigator Magazine
From: Robert VanderPol II
Date: 2016 May 10, 19:24 -0700
From: Robert VanderPol II
Date: 2016 May 10, 19:24 -0700
While the ON article is correct that the median is a statistically more valid value, it is also not computationally efficient. The ON method described only works well if you are using electronics for the sight reduction. If I were doing it manually, the only way I would use that method is if it involved a critical landfall with obscured hazards offshore and/or I had a lot of time to kill. Actually, for manual reduction there is a subset of celestial measurements that the median would work for, specifically those that involve the altitude being at a constant or almost constant height: the noon shot, polaris or any body that is approaching meridian passage. Pick the median altitude and associated time then reduce just the one data point. Other than the average there is a graphical method I think would work generally. Graph the data points, eyeball a line to fit the data, then pick the one closest to the line and reduce that. All in all I think I will stick with averaging 3 to 5 sights. --------------------------
