NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Derrick Young
Date: 2011 Dec 13, 15:03 -0500
You need to look at which earth model is being used for the Almanac, Henning’s, the online almanacs as well as your GPS. The variation of several nautical miles is not unusual with the different models.
Derrick Young
DeCA/CARTS PMO
804-734-8000, x48561
804-332-4025
Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more." --Nikola Tesla, Austrian-American inventor and engineer
From: navlist-bounce@fer3.com [mailto:navlist-bounce@fer3.com] On Behalf Of Fred Stevens
Sent: Tuesday, December 13, 2011 1:44 PM
To: NavList@fer3.com
Subject: [NavList] Position discepancy
I have a known location... well, "known" as far as Google
Earth goes. I am assuming that it is a correct position
since it is verified by GPS. When I go to either the NA or
online almanacs, like USNO Almanac or Henning Umland's to
verify the coordinates using Jupiter and Polaris, there is
always a significant discrepancy between them and those from
GPS/GoogleEarth, a few nautical miles at the very least.
Enough to be worrisome if at sea.
Any idea why so much difference?
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