NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: CelNav without sextant
From: Bill Noyce
Date: 2004 Nov 2, 15:40 -0500
From: Bill Noyce
Date: 2004 Nov 2, 15:40 -0500
As another way to use rising and setting of stars -- how about using the compass to identify the azimuth at which some circumpolar stars rise and set? I suspect that could tell you your latitude with reasonable accuracy, even without a watch. Even if you can only read the compass to a couple of degrees, I think the uncertainty in such a latitude will depend more on the uncertainty of refraction at the horizon. For example, consider a star whose path just grazes the northern horizon -- that tells us our latitude without being very dependent on the azimuth measurement. With a watch, you can get latitude from the length of time a star far from the equator is above (or below) the horizon. Perhaps you could also estimate when it's directly in line with the celestial pole, allowing you to measure some stars whose rise or set occurs during the day. -- Bill