A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Andrés Ruiz
Date: 2020 May 19, 21:14 +0200
There is a slight misunderstanding about the nature of certain types of Lines of Position, LoPs.
The Bisertor of two Azimuths, azimuth difference, is a hyperbolic LoP.
The circumference of equal altitude or Circle of Position, CoP, is a small circle.
· If Ho = 0º The CoP becomes a GC
· If Ho = 90º CoP becomes a point: the GP, illuminating pole of the observed star or substellar point.
The LoP based on a Horizontal Angle, used in coastal navigation with a sextant, are two circles of position. And they are not a isoZ either.
Several of these LoPs are plotted on a map with my CharWork application.
See attached examples of Horizontal Angle LoPs from http://dept.navigation.enmm.free.fr/navigation.htm (Permission allowed)