NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigation Weekend: summary and thanks
From: Frank Reed
Date: 2008 Jun 22, 22:23 -0400
From: Frank Reed
Date: 2008 Jun 22, 22:23 -0400
Ken, you wrote: " I did not mean to imply that Bowditch's equations (as presented by Joel) would not work at the time of the equinoxes. Its just that I could think of one case where if both altitudes were zero (sunrise and sunset) it could not work. This is the well known emergency procedure of finding latitude by length of day, which gets less accurate as the equinoxes are approached. " Aha. Yes, I see what you mean now. Fundamentally, it fails for that pair of sights (alt=0, azm=90 at sunrise, alt=0, azm=270 at sunset) because those sights yield parallel LOPs, both running north-south. -FER --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---