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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Timed Noon sights for position
From: Fred Hebard
Date: 2004 Jan 22, 16:42 -0500
From: Fred Hebard
Date: 2004 Jan 22, 16:42 -0500
On Jan 22, 2004, at 4:07 PM, Noyce, Bill wrote: > I'm still confused. Suppose the procedure you suggest does give > a reliable latitude (I have some questions about that, but don't > want to discuss them until I'm sure I understand the procedure.) > It looks to me as if you must then choose among some of the following > alternatives for a longitude: I'm no expert on navigation, but isn't the following the basics?: The noon sight gives your latitude directly as lat = 90 - altitude + declination, where north declinations are positive for sights from the northern hemisphere. No time involved. The time at which you make the sight is noon, local time, and that with GMT gives you longitude, with suitable correction using the equation of time. You get GMT from the chronometer or the radio.
