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Re: Sextant Positions versus Map Datums?
From: Bill Murdoch
Date: 2002 Jan 18, 11:29 AM
From: Bill Murdoch
Date: 2002 Jan 18, 11:29 AM
Aren't we missing the original question ? > How does the WGS84 ellipsoid compare with the astronomers one? From the coordinates systems section of the website mentioned earlier: http://www.colorado.edu/geography/gcraft/notes/coordsys/gif/difsys.gif the position of the star in the hand of the Goddess of Liberty atop the capital dome in Austin, Texas is: NAD 83 -- 30:16:28.82N, 97:44:25.19W NAD-27 -- 30:16:28.03N, 97:44:24.09W WGS-72 -- 30:16:28.68N, 97:44:25.75W If I were to climb to Libery's shoulder, sit on the star, and determine my position with a sextant, a bowl of water, the Nautical Almanac, sight reduction tables, and the heavens (and do it perfectly), what would the position of the star be ? If I were to do the same from every point on the surface of the earth, where would I find the greatest deviation from the position determined by a GPS set to (say) WGS84 ? Bill Murdoch
