NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Pilots and Mariners
From: Brian Whatcott
Date: 2002 Feb 7, 20:59 -0600
From: Brian Whatcott
Date: 2002 Feb 7, 20:59 -0600
At 03:42 PM 2/7/02, Chuck Griffiths wrote: >... Most >pilots flying around the states plotting their "courses" on aeronautical >charts >are plotting rhumb lines on Mercator projections. ... >they generally follow radio navigation devices that >guide airplanes over great circle courses. Good marine navigators, of course, >know that a radio bearing to a distant non-directional radio beacon is the >initial bearing of the great circle track to that aid, and plot it >accordingly. ... >Chuck It has already been noted that airmen in fact, plot great circles on conical orthomorphic charts. The straight line on the conical orthomorphic has a different starting direction than the end. But it raises an interesting point: there is a class of navaids intended to indicate magnetic radial bearings - the VOR. This too radiates great circle radials if the distance is extended far enough - so that at long range, the indicated magnetic radial is somewhat wrong.... Brian Whatcott Altus OK Eureka!
