NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: fix with the noon shot...
From: Tony S
Date: 1997 Oct 28, 7:20 PM
From: Tony S
Date: 1997 Oct 28, 7:20 PM
PULEEZE ...folks! This same proposition (in many cases nicely thought out _in theory_) is proferred about every three months on this very list. I offer for your learned consideration: 1. If a true "fix" were possible, it would be heralded in any and every navigation text you might have ever read. 1a. A fix by definition is the most accurate position that can be attained by the navigator by (in this case) celestial means. 1b. The sloppy navigator can, of course, obtain a _rough_ _estimate_ of longitudinal position by making many compromises. If he has not the slightest idea of his longitude, it is better than nothing (Chuck was on the mark here with lifeboat nav). 2. While theoretically possible, EVERYTHING near LAN depends on _absolute_ accuracy of the sextant altitude sight, time and related factors. (delta declination, North/South, East/West sailing tracks are _only_ a very _minor_ part of the equation). The best method is to bow to well proved practices of well time-spaced running fix ...then one can call it an "Rfix". (But, still certainly not as good as a true celestial fix). Sorry to be so didactic, but the proposition keeps coming up as earlier mentioned ...with some folks proferring "a new revalation". Everything depends on what measure of innacuracy _you_ are willing to accept. SURELY, NO ONE would accept such rough approximations in approaching atolls or landfall! A Navigator's well kept DR since last true fix is very probably much better. Wasted words? I hope not! Bye. Tony San Francisco, CA (Home of NAVIG94) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-= =-= TO UNSUBSCRIBE, send this message to majordomo@ronin.com: =-= =-= navigation =-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=