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Re: Oblateness correction
From: Andrés Ruiz
Date: 2010 Nov 30, 20:38 +0100
From: Andrés Ruiz
Date: 2010 Nov 30, 20:38 +0100
Yes.
See at my web the paper "Corrections for Sextant Altitude" +N/-S for B: latitude
in
fact, this correction is significant for the moon, but can be applied to any celestial body.
Regards
2010/11/30 Lars Bergman <lars.h.bergman@gmail.com>
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