NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: AN5954 bubble octant by Bausch and Lomb
From: Gary LaPook
Date: 2012 May 8, 10:11 -0700
From: Gary LaPook
Date: 2012 May 8, 10:11 -0700
Take another look at what I did. If you are taking multiple readings of the altitude of the horizon with a marine sextant for the purpose of determining index error then you are right, that readings should be constant. I was not doing that, I was measuring the rapidly changing altitude of the sun over a four minute period. My purpose, on that occasion, was to determine the index error but the sun didn't know that, for all it knew I was taking these altitudes for the purpose of finding a small island. My results show what results from taking a series of sights for the purpose of navigation, and averaging them or taking their median. Note the conclusion that the possible error from using the median instead of the arithmetic mean for the
purpose of navigation is only 2.3 NM, nowhere near the error that you postulated so, that for the purpose of normal navigation, the " median is [ NOT] useless." --- On Tue, 5/8/12, Alexandre E Eremenko <eremenko@math.purdue.edu> wrote:
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