NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Non Electronic Sight Reduction
From: Greg Rudzinski
Date: 2009 Dec 13, 18:07 -0800
From: Greg Rudzinski
Date: 2009 Dec 13, 18:07 -0800
Today I was able to work a morning Sun line five different ways using just tables (Pub. 249, Weems, Dreisonstok, Ageton, and Trig/Log). The LOP results were all within one nautical mile of each other. The only interpolation done was for Declination using Pub. 249. One side of one sheet of paper easily contained all five reductions. Personal impressions of the various methods Rank: 1. Pub. 249 2. Weems Line of Position 3. Dreisonstok Pub. 208 4. Ageton Pub. 211 5. Trig/Log Tables Pub 249 is exceptionally fast to use but is a large table. Intercepts can be large. Declination limited to 29° on volumes 2 and 3. Weems and Dreisonstok are very quick with Weems coming out on top with the use of a graphical solution for determining azimuth. Ageton involves an extra summing but is a bit more accurate. Intercepts are short due to using the DR position as the assumed position. Trig/Log tables involve the most summing and table page turning but still practical and accurate. Intercepts are short due to using the DR position as the assumed position. An excellent companion to a calculator or sliderule. I like all of the above methods and recommend that navigators give each a try to determine the best clutch of tables to keep on hand. Even though Ageton Pub. 211 ranks 4th it is stowed in my sextant case because it is thin and compact. -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com