NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The *&^%$#@ Moon
From: Lars Bergman
Date: 2006 Aug 18, 02:15 -0500
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From: Lars Bergman
Date: 2006 Aug 18, 02:15 -0500
Regarding Robert's trouble with the
moon,
I see
no reason why moon shots should be worse than any other body; but there are two
things to consider:
1. The
"moon street", i.e. the light from the moon on the water's surface, do not
(always, seldom ?) reach the horizon, so shots at night tend to
yield too large altitudes. A daylight shot does of course not suffer from
this. And with a bubble sextant there should be no problem with this
issue.
2.
Sometimes it can be very difficult, or actually impossible, to know whether the
upper or lower limb of the moon is the one to shoot. Then you'll have to
wait an hour or so until the moon has tilted suffiently to show a clear
limb but near full moon it is easy to make mistakes. A false LL gives a too
large altitude, a false UL gives a too small altitude.
Lars
59N
18E
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