NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: How Many Chronometers?
From: Mike Burkes
Date: 2009 May 7, 17:13 -0700
From: Mike Burkes
Date: 2009 May 7, 17:13 -0700
Hi folks, yes indeed this method also discussed in "Self Contained Celestial Navigation" by John Letcher Chap 17 pgs 96-105. Pretty neat indeed. Mike Burkes On May 7, 4:40�am, Geoffrey Kolbewrote: > List member John Karl, in his book "Celestial Navigation in the GPS Age", > has a nice little section on page 73 entitled Time from a Lunar LOP and a > Star Fix. The essence of the method is the LOPs from a number of star fixes > will cross neatly at a given point on the chart, but that point will in > error in longitude due to the error in the chronometer. The longitude error > in a lunar LOP will be slightly different due to the faster motion of the > moon across the sky. The trick then is to adjust the time so that all LOPs > - including the lunar LOP - cross at the same point. The amount of > adjustment required gives the error in the chronometer. > > I had not seen this described before and thought it quite neat. > > Geoffrey Kolbe --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---