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)
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