NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Cannot dispense with the assumed position at sea
From: Jim Thompson
Date: 2004 Feb 19, 22:36 -0400
From: Jim Thompson
Date: 2004 Feb 19, 22:36 -0400
Everybody has different semantics, is all; I think that we are all saying the same thing functionally. Our CN course uses "AP" to mean the entering argument for calculating Hc, similar to Henning Umland's "IP" (initial position). That AP (IP) can be: - A DR or any other similarly precise position, if the sight reduction tables or formulae that we are using accept fractions of lat and long. - A nearby rounded lat/long position, if the sight reduction method cannot accept fractional positions. Our course discourages using an EP as an initial position, although I understand that is debatable. The degree of confidence that the navigator has in an EP plotted on a celestial LOP is directly proportional to the degree of confidence he or she has in the initial position used to plot the LOP in the first place. See http://jimthompson.net/boating/CelestialNav/CelestNotes/SightReduction.htm#D eadReckoning and http://jimthompson.net/boating/CelestialNav/CelestNotes/Plotting.htm and http://jimthompson.net/boating/CelestialNav/CelestNotes/Definitions.htm for the conventions that we are using. Jim Thompson jim2@jimthompson.net www.jimthompson.net Outgoing mail scanned by Norton Antivirus -----------------------------------------
