NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Averaging
From: Jim Thompson
Date: 2004 Oct 19, 08:48 -0300
From: Jim Thompson
Date: 2004 Oct 19, 08:48 -0300
> -----Original Message----- > From: Navigation Mailing List onBehalf Of Peter Fogg > Getting back to nav, the process for averaging sights is simple > and effective. As many sights as possible > taken over about 5 minutes of time are plotted. Time is the > horizontal axis, observed altitude on the > vertical. The slope of this group of sights either rises; obs to > the east, or descends; to the west. This slope > is then compared to a calculated line, which is then best fitted > to the slope of sights. Any extreme outliers > are disregarded (probably best, although it goes against ideal > statistical practice). > Simple and effective. I'm always vaguely surprised its a > technique not more widely known. Microsoft Excel makes it drop-dead easy to draw such a graph and, with a mouse click, to generate the equation for the line of best fit. If a laptop is at hand. Jim Thompson jim2@jimthompson.net www.jimthompson.net Outgoing mail scanned by Norton Antivirus -----------------------------------------
