NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Haversines with Logarithms
From: David C
Date: 2020 Oct 18, 19:05 -0700
From: David C
Date: 2020 Oct 18, 19:05 -0700
Brian Wrote
The log-haversine tables I have in hand return Right Ascension or Hour Angle by having both scales printed along the top and bottom, and both edges. The logs are to base 10, and the exponent has 10 added to help simple sailors like me, rather than “bar 1” as taught once at school.
Haversine tables are entered with an angle. In Inmans 1932 and Norie 1918 the angle can be an arc or a time. For example log hav 8hr 30min = 9.90546 and log hav 127° 30' is also 9.90546. This is because 8hr 30min (time) = 127° 30' (arc).
It is incorrect to say tha the log-haversine tables return Right Ascension. The tables return an angle that can be expressed in various formats. If I knew how to do it I could convert 8hr 30' to radians!!!!!
