NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Rust's diagram for computing azimuth
From: Gary LaPook
Date: 2007 Oct 08, 11:42 -0700
From: Gary LaPook
Date: 2007 Oct 08, 11:42 -0700
Gary LaPook writes: Attached is Rust's diagram for computing the azimuth of the sight which was included in Weems "Line Of Position Book," 1927. It was developed using the sine formula. You enter on the left with LHA and go to the right to the declination then straight up to the altitude then to the right to the azimuth. Also included is a table used to determine in which quadrant the azimuth falls when the body is close to east or west. This diagram can be used with any set of tables, H.O. 208, H.O. 211, etc., and the extra steps used in those tables to compute the azimuth can be disregarded. The shape of these curves show the potential loss of accuracy using the sine formula as the azimuth approaches 90º as the altitude curves become almost vertical and only slight changes in altitude results in large azimuth changes. -- --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---