A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Andrés Ruiz
Date: 2010 Nov 30, 20:38 +0100
In the Sight Reduction Procedure chapter in the Nautical Almanac, the correction for the oblateness of the earth, to be added to the Moon's parallax in altitude, is given (in degrees) as
OB = -0.0032 (sin Lat)^2 cos H + 0.0032 sin (2 Lat) cos Z sin H
where H is apparent altitude, Z true azimuth in the range 0 ... 360 and Lat is latitude in the range -90 ... 90. Now, in the second term the sine of two times latitude gets different signs depending on hemisphere. Shall it be like this, or ...?
Lars, 59N 18E