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    Re: Position discepancy
    From: Gary LaPook
    Date: 2011 Dec 13, 13:00 -0800
    I don't know exactly what you are saying. Did you take observations of Polaris and Jupiter with a sextant? Bubble sextant? Marine sextant? sea horizon? artificial horizon? Did you make all the necessary sextant corrections? Did you reduce the sights using the Navy calculator with your known position?


    We need more information.


    --- On Tue, 12/13/11, Fred Stevens <fredstevens@yahoo.com> wrote:

    From: Fred Stevens <fredstevens@yahoo.com>
    Subject: [NavList] Position discepancy
    To: NavList@fer3.com
    Date: Tuesday, December 13, 2011, 10:43 AM

    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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