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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant accuracy (was : Plumb-line horizon vs. geocentric horizon)
From: Bill B
Date: 2005 Feb 20, 20:16 -0500
From: Bill B
Date: 2005 Feb 20, 20:16 -0500
> So if I were to use a distant power line (or other narrow straight feature) to > get the index correction of my sextant, I should be able to get very accurate > results. But what about the sea horizon? Can the eye detect discontinuities in > the visual horizon (which is not a line but instead a boundary between light > and dark) with the same hyperacuity? Question. Given the problem with using a near object is parallax error created by the index mirror being higher than the horizon glass. Could one use a nearer power line at some measurable distance, and adjust that IC with a parallax correction using the vertical distance between the centers of the index and horizon mirror vs. the distance from the power line? Bill