A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Samuel L
Date: 2014 Dec 24, 14:00 -0800
Well, I'm doing these calculations because I want to. It's an excercise in math and curiosity . You're correct- the "LHA" figure is the difference in Longitude between the two locations. In Bowditch "Sailings" chapter, as mentioned previously, they use HO 229 with the difference in Longitude as the LHA for part of the solution to the problem.
The plots are the easy part and were done a few days ago. That's why I knew the Azimith was about 4d. So, the formulas I was experimenting with should've provided the answer with no ambiguity.
It does seem that no one is really doing this sort of stuff (Great Circle route calculations) anyway.
Peter's spreadsheet, sailings.xls is available here;
Page down a ways and you'll find it.