NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Correct way to calculate time of LAN?
From: David Fleming
Date: 2017 Feb 6, 20:25 -0800
From: David Fleming
Date: 2017 Feb 6, 20:25 -0800
You are having trouble with E and W longitude. Simplest would be to figure GHA for your DR.
ie If DR is 175d 5.2m E then you are at 180d + (180d -175d 5.2m) of GHA
or 180d + 4d 54.8m = GHA ( 184d 54.2m)
Look for largest GHA less than that in Almanac and use increments to find time past amanac entry required to make up the differenc in GHA from almanac to where you are.
