NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: On checking accuracy
From: Greg R_
Date: 2008 Aug 4, 15:19 -0700
From: Greg R_
Date: 2008 Aug 4, 15:19 -0700
--- Peter Foggwrote: > However, its not the article on the Starpath site that I think I > remember (I know ..). THAT one (in my wild erratic fancy) showed > how an outlier can lead to quite a wrong slope, if all you had to > work with was the data points themselves. Bill, does this ring any > bells? Anyone? Actually, I think that may be the one you're thinking of (I've read both of his articles on sight-averaging and metal vs. plastic sextants and remember what you're speaking of). This particular article writes about having 4 sights plotted on graph paper, and the inclination to throw the 2nd sight out as being off the slope of the other 3. But later analysis by reducing a pair of sights at the beginning and the end of the shooting session (to derive a more accurate slope, rather than just an average of the 4 sights) shows that the 1st sight is the one that's off the slope and not as accurate as the others. -- GregR --- Peter Fogg wrote: > > There. That's a simpler, more relevant Subject, is it not? > > Bill has kindly sent me a David Burch article entitled "How to > Average > Celestial Sights for Optimum Accuracy". That helped me to find the > online link: > http://www.starpath.com/resources2/sight_average.pdf > > Its a nice explanation and I recommend it. However, its not the > article on the Starpath site that I think I remember (I know ..). > THAT one (in my wild erratic fancy) showed how an outlier can lead to > quite a wrong slope, if all you had to work with was the data points > themselves. Bill, does this ring any bells? Anyone? > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---