NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: GPS direction: Rumb line or great circle
From: Douglas Denny
Date: 2009 Oct 3, 04:42 -0700
From: Douglas Denny
Date: 2009 Oct 3, 04:42 -0700
I was reading the post on the mecca direction question and was wondering; when a (Garmin) GPS indicate a direction, does it follow a rumb line or a great circle? GPS uses spherical trigonometry so the answer is Great Circle. A rhumb line is a special curve called a loxodrome which spirals out from pole to pole. It has the special property of maintaining a constant angle to the meridians. Hence on a mercator chart it is a straight line from place to place. Douglas Denny. Chichester. England. --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---