NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Computaion of table of offsets.
From: Gary LaPook
Date: 2007 Oct 29, 02:01 -0700
From: Gary LaPook
Date: 2007 Oct 29, 02:01 -0700
In the discusssion of the St. Hilaire method the subject of the table of offsets used to approximate the curved LOP came up. This is table 4 in Bowditch (1975 ed), table 19 in the online Bowditch and is also printed in each volume of H.O. 229. Bowditch gives the formulas for this calculation and one of the formulas gives the radius of the circle of postion. The formula for this is: R = 3438' cot altitude. Ruiz gives a similar formula: R = (60*180/pi) cot altitude which reduces to the other formula given in Bowditch. My question is why do you use this formula? Why isn't the radius of the circle of position simply 60 times the zenith distance? This is the formula we have always used for plotting high altitude circles of positions around the GP. Should we use the Bowditch formula for this purpose also. gl --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
