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Re: [Nml] Sunset sight?

Subject: Re: [Nml] Sunset sight?
From: Pierre Boucher (pboucher@XXX.XXX)
Date: Thu Oct 29 1998 - 01:57:13 EST

At 17:07 28/10/98 -0800, you wrote:
>Would it be possible to find position (or at least longitutde), without a
>sextant by marking the time at sunset and going to the tables with 0 degrees as
>the altitude?

First you would not get longitude unless the Sun sets due West wich happend
only twice a year at equinoxes.
In the Northern Hemisphere the sun's azimut as it sets will be around 300d
(at lat. 40d N) on the first day of summer and decreasing bit by bit till
the equinox day. After that day it will keep on decreasing til it reach
more or less 240d.

As an emergency solution (life raft and sitting flat on the bottom) we teach
to use -0d53' as the observed altitude exactly at the moment that the UL of
the Sun touches the horizon. One thing to remember is that if the
calculated altitude ended to be also negative, that -0d35' is greater then
-0d53'.

Pierre Boucher N
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