NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sun Moon Lunars to 155 degrees
From: Peter Hakel
Date: 2010 Apr 2, 13:21 -0700
Peter Hakel
From: Antoine Couette <antoine.m.couette@club-internet.fr>
To: NavList@fer3.com
Sent: Fri, April 2, 2010 10:46:38 AM
Subject: [NavList] Re: Sun Moon Lunars to 155 degrees
ADDITIONNAL EFFECT DUE TO (DIFFERENTIAL) REFRACTION WHICH DISTORTS THE SHAPE OF THE SUN AND OF THE MOON
[parts deleted by PH]
From: Peter Hakel
Date: 2010 Apr 2, 13:21 -0700
My thanks to Kermit for his excellent explanation of the terminology. So,
Flattening: not quite spherical shape of the Earth
Oblateness: refraction-induced "apparent flattening" of the observed Sun or Moon disc.
All clear now.
Flattening: not quite spherical shape of the Earth
Oblateness: refraction-induced "apparent flattening" of the observed Sun or Moon disc.
All clear now.
Peter Hakel
From: Antoine Couette <antoine.m.couette@club-internet.fr>
To: NavList@fer3.com
Sent: Fri, April 2, 2010 10:46:38 AM
Subject: [NavList] Re: Sun Moon Lunars to 155 degrees
Dear Peter,
When clearing Lunars, two effects can sometimes be significant and each of them can independently affect the resulting cleared Lunar distance by at least 0.1'.
ADDITIONNAL PARALLAX CORRECTION RELATED TO THE FLATTENING OF THE EARTH
ADDITIONNAL EFFECT DUE TO (DIFFERENTIAL) REFRACTION WHICH DISTORTS THE SHAPE OF THE SUN AND OF THE MOON
[parts deleted by PH]