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Topic: Celestial Navigation on land - corrections for altitude?
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John Pinto
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posted May 06, 2021 05:18 PM
In using the methods of Celestial Navigation as taught in the CelNav book are there any changes necessary if using these methods for land navigation (other than using dip short or artificial horizons)? Specifically do we need to make adjustments for our altitude above or below sea level to get accurate fixes?
Or are the procedures the same whether we are at sea level or up in the high deserts of Utah or below sea level in Death Valley where your altitude above sea level can reach 10,000 feet or below sea level reaches -300 feet? I wasn’t sure if for example it would affect our corrections for refraction (or any other unusual corrections).
From: Orlando
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David Burch
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posted May 07, 2021 08:30 AM
When using an artificial horizon at any elevation or when using dip short at the shore of a high mountain lake, there are no special corrections to be made. All is done there as we would if doing the same thing at sea level.
(We cannot of course, stand on a high hill or mountain with a nice view of the ocean horizon, a long way off, and use that without proper dip.)
From: Starpath, Seattle, WA
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John Pinto
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posted May 11, 2021 12:27 AM
I just got my copy of pub. 249 and there are different refraction corrections in it for elevations above 5000 feet (Table 6 in vol. 2&3, Table 8 in vol. 1) that does differ from those corrections at sea level. Doesn’t look like much difference until you get above 10000 feet and low sights. Probably not enough to be concerned about unless you are doing celestial navigation in very high elevations.
From: Orlando
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