NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Position discepancy
From: Gary LaPook
Date: 2011 Dec 13, 14:04 -0800
From: Gary LaPook
Date: 2011 Dec 13, 14:04 -0800
| The Hc from the site is not what would have been measured with a sextant. If you are using a nav program that reduces a sight for you then it probably needs as an input the sextant altitude to which it will make corrections to come up a fix. So, you probably need to UN-correct the value you take from the almanac program and then use that value to put in the reduction program. For instance, you will need to add the refraction correction also found near the right of the almanac table to the Hc. You nav porgram should also take as inputs you height of eye (or dip) set to zero and set index error to zero. For Polaris and Jupiter that should solve your problem. Go back and compare your errors with the refraction corrections for the same time and place and body, they are probable the same. gl --- On Tue, 12/13/11, Fred Stevens <fredstevens@yahoo.com> wrote:
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