NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: A Practical Nav Problem
From: Frank Reed CT
Date: 2006 May 24, 05:24 -0500
Fascinating scenario! For now, I just have a quick comment on one small
issue. You wrote:
"One thing to keep in mind is that the declination of the sun during the
first half of April is from 5 to 10 deg N (and increasing), which means it
will be fairly close to the zenith. In my experience, that makes it harder
to get latitude from a noon sun site. "
Historically, navigators did not mind getting latitude when the Sun was very
close to the zenith. In the logbooks they even seem to get a kick out of it.
I think the modern aversion to high altitude sights is due to a specific
method of "swinging the arc" which became popular around 1940 +/-10 years.
There's really no reason why a navigator should not be able to get good altitudes
even when the object observed is close to 90 degrees altitude.
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
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From: Frank Reed CT
Date: 2006 May 24, 05:24 -0500
Fascinating scenario! For now, I just have a quick comment on one small
issue. You wrote:
"One thing to keep in mind is that the declination of the sun during the
first half of April is from 5 to 10 deg N (and increasing), which means it
will be fairly close to the zenith. In my experience, that makes it harder
to get latitude from a noon sun site. "
Historically, navigators did not mind getting latitude when the Sun was very
close to the zenith. In the logbooks they even seem to get a kick out of it.
I think the modern aversion to high altitude sights is due to a specific
method of "swinging the arc" which became popular around 1940 +/-10 years.
There's really no reason why a navigator should not be able to get good altitudes
even when the object observed is close to 90 degrees altitude.
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
