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    Re: Extremely poor conditions??Atomic Clocks
    From: David Fleming
    Date: 2012 Mar 23, 07:20 -0700

    Given the expected rate error in a quartz clock and a premium for memory in a updateable atomic clock it is reasonable to assume only a seconds error for such a clock. Ie a programmer might make such an assumption. So If a clock had not been updated for say half a year and then made contact with the WWV it could have the seconds right but be off by a minute. But is it likely that the clock wasnt updated for such a long time? No.

    Also a one minute time error would show a trending altitude error as the sun follows a parabolic path in the sky. How noticeable that would be I haven't evaluated?

    On the other hand let me quote Bowditch, 1984 1605. Dip:

    4th paragraph

    The values given in the table are satisfactory for practical navigation. An investigation by Carnegie Institution of Washington showed that of 5000 observations at sea, value differed from tabulated value by more than 2.5', except for one difference of 10.6'. Extreme values of more than 30' have been reported and even values of several degrees have been encountered in polar regions. Greatest variations from tabulated values can be expected in calm weather, with large differeences between sea and air temperatures, particularly if mirages are present. etc.
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