NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Full moon sights and lifeboat sextant accuracy
From: Bruce Cutting
Date: 2017 Oct 6, 18:20 -0600
From: Bruce Cutting
Date: 2017 Oct 6, 18:20 -0600
I'd like to see results from a set of runs, one with the MK3 another with a "good" sextant under the same conditions. These results do not seem too bad to me. Certainly good enough to put on a reasonable sized island. > Jing, > The Davis MK 3 accuracy is in the + or - 8' range out of the box. Better > results are possible but you have to earn it. Plastic sextants will warp > in direct sun light or if squeezed too hard. I zero the index error before > each observation then check again after the observation. Even if > everything is done right there will remain large systematic errors. Below > is a set of 5 observations using a Davis MK 3 and a liquid artificial > horizon today. Good enough in a pinch but not very good as a primary > sextant. > Intercepts: > 3.7' toward > 2.0' toward > 2.8' toward > 3.0' toward > 1.4' toward > The MK 3 is very good for horizontal sextant angles, and relative bearings > off the bow. Sailboat racers can use to see if gaining or losing on a > competitor. > Greg Rudzinski > > [plain text auto-generated] > ---------------------------------------------------------------- > NavList message boards and member settings: http://fer3.com/NavList > Members may optionally receive posts by email. > To cancel email delivery, send a message to NoMail[at]fer3.com > ---------------------------------------------------------------- > ---------------------------------------------------------------- > > > : > http://fer3.com/arc/m2.aspx/Full-moon-sights-lifeboat-sextant-accuracy-Rudzinski-oct-2017-g40294
