NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Bubble horizon
From: Geoffrey Kolbe
Date: 2002 Dec 17, 08:52 +0000
From: Geoffrey Kolbe
Date: 2002 Dec 17, 08:52 +0000
Robert Eno wrote: >To make a long story short, unless you can adjust the size of the bubble, >you will experience errors; sometimes gross errors. I, and I am sure some others on the list, would be grateful to Robert if he could make this short story a little longer. Why is the size of the bubble critical? Is Robert concerned that the damping of the bubble movement is a function of bubble size, or that the accuracy with which the celestial object can be centered in the bubble is a function of bubble size, or some other consideration? To answer George Huxtable's question on the sort of accuracy one should expect from a bubble sextant. I have a Link A-12 aircraft sextant (still available from Celestaire, last time I looked,) and I would expect an altitude measurement to be within +/- one minute. I am disappointed if I am two minutes out and I cannot remember the last time I was more than two minutes out. Geoffrey Kolbe.
