NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Meridional Distances
From: Arthur Pearson
Date: 2002 Sep 17, 19:28 -0400
From: Arthur Pearson
Date: 2002 Sep 17, 19:28 -0400
Lest the authors of the Silicon Sea legs think their work unappreciated, I for one have begun working the legs. I worked the last leg published primarily using the Traverse Tables in a 1965 version of Bowditch that give very similar results to the official answers. I note that when I downloaded the tables from the current version of Bowditch online, the current configuration if the tables is much less flexible and precise than the '65 version. Although one has several table lookups to get a solution, the older tables allow solution of problems <1,000 nm with ease. -----Original Message----- From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of Peter Fogg Sent: Tuesday, September 17, 2002 6:53 PM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Meridional Distances Have recently come across a new (to me) method of calculating rhumb line courses and distances, and also traverse calculations, where the starting position, course and distance are known, and the finishing position needs to be calculated. The method uses not just Meridional Parts, with which I am familiar, but also Meridional Distances, which are new to me. Although I have tables accurate to 2 decimal places for the Meridional Parts, the Meridional Distances come only in whole degrees, so need to be interpelated for in-between values. Despite this the method is simple and straight-forward enough, no more complex or prone to error than alternative methods. I am told it is particularly accurate, although I don't know if there is any way to check this. Used on old Silicon Sea problems it gives answers similar but not identical to the official answers, but then so do other methods - mostly! With a new Silicon Sea leg in the offing I intend to post a comparison of a few different methods (assuming it contains any such problems) and let others compare the results with their own methods.