NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Spherical triangles versus plane triangles
From: Ian Staniforth
Date: 2025 Sep 17, 11:39 -0700
From: Ian Staniforth
Date: 2025 Sep 17, 11:39 -0700
If anyone is interested, there is a Python program here which calculates the plane, spherical, and ellipsoidal (WGS84) distance between two points on the Earth's surface. You could convert it into your favourite programming language or spreadsheet. The code for the ellipsoidal distance uses Andoyer's method (cf Meeus, Astronomical Algorithms p.85).
