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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Practice Bubble vs. Professional Bubble
From: Bill B
Date: 2012 Aug 05, 18:30 -0400
From: Bill B
Date: 2012 Aug 05, 18:30 -0400
On 8/5/2012 6:17 PM, Alan S wrote: > I have tried the practice bubble horizon without successa, possibly my > fault, the thing seems "tricky" to use and I have yet to get an > understandable explaination of the bubble correction factor, as with how > to determine it, .... It is simply a matter of looking at the difference of Ho and Hc from a known position (plus/minus IE). Under the K.I.S.S. principle, I determine LAN for my location, and do several observations while the sun's elevation changes very little. I also preset for Hs. In an attempt to minimize centering the bubble errors while aligning the sun, I had tripod mounted my preset sextant with the bubble as close to centered as I could see it. Even then results were plus/minus 2', so accurately seeing bubble placement is a limiting factor. Bill B
