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From: Zorbec Legras (no email)
Date: Fri Sep 03 2004 - 12:31:39 EDT
----- Original Message -----
From: "Noyce, Bill" <>
Date: Fri, 3 Sep 2004 09:13:03 -0400
To:
Subject: Re: Beginner Meridian Passage Question
> > > b) when you think Polaris is directly below or above the pole, add
> or
> > > subtract its difference (which you have memorized as about 45');
============================
Latitude by pole star.
Lat = true altitude + corr 1 + corr 2.
Corr 1 = Pd * Cos LHA
Corr 2 = ((sqr Pd)/2.3438) * sqr sin LHA * tan true altitude.
Pd = pole distance = 90 - dec.
============================
Latitude by meridional transit.
Upper transit:
Lat = Zd + dec (1)
Zd = zenithal distance (= 90° - true altitude).
+ Zd if elevated pole in your back
- Zd if your are facing elevated pole.
+ dec if same name as latitude
- dec is diff name.
Lower transit
Lat = 180° - (Zd + dec)
==============================
Ex meridian (if you miss the transit)
Vers meridional Zd = vers (90° - true altitude) - (vers LHA * cos assumed Lat * cos dec)
with the meridional Zd use formula (1) to compute the Latitude.
Vers x = versine x = sinus verse x = 1 - cos x
==============================
About the elevated pole, have a dry gin and read it again...
The elevated pole is the pole in the same hemisphere as the zenith.
==============================
It's hard to be a hero on this planet, one to beam up...
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