NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigation exercise
From: George Huxtable
Date: 2008 May 28, 15:30 +0100
From: George Huxtable
Date: 2008 May 28, 15:30 +0100
Bypassing all that guff from Frank, capital-letter emphasis and all, about longitude around noon, which was notably lacking in numerical detail, I will boil it down to a simple matter. Take the example that I suggested, a vessel approaching the Clyde in midwinter, in latitude 56 degrees. Her navigator spends 40 minutes on the bridge, around noon, measuring altitudes of the Sun to determine his longitude. Given that his sextant altitudes are precise enough to determine latitude to 1 mile, just how good are they required to be to determine his longitude to within 5 miles, as Frank claims he can? A complete error-budget is requested, with due allowance made for any errors in ship's speed and course through the water and rate and direction of tidal set, stating the precision with which they need to be known. George. contact George Huxtable at george@huxtable.u-net.com or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
