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    Re: Atomic Clocks
    From: Lu Abel
    Date: 2012 Mar 23, 09:14 -0700
    Interesting behavior...   

    Which brings up a couple of points:

    1.  A good navigator understands (and even seeks out) any problems with his or her tools.  

    2.  As available tools become easier to use, they also become more complex to understand and to even check out.   In celestial, we have an orderly and quite visible procedure for going from a sextant shot to a line of position.  A bit of spherical trig, but basically the numbers are all there for us to see.   On the other hand, there is this magic box called a GPS -- it displays a position far more accurately than we can get with celestial, but with no chance for us to understand how it is doing it.    

    Do we even trust clocks?  Over the years we have developed ways to track the behavior of chronometers so we can decide that we "trust" them.  But we also keep them nestled and gimballed in padded boxes so that odd bumps and heaves won't affect them.   Maybe we should check our clocks out by doing Lunars??

    Oh, and then there's our almanacs.   Printed on good, old fashioned paper (to some, more trustworthy than an random computer display) but where do they come from?   Computers....    At least we know that these almanacs come from the joint efforts of two national observatories who therefore have some responsibility for their correctness. 


    From: Greg Rudzinski <gregrudzinski---.com>
    To: NavList@fer3.com
    Sent: Friday, March 23, 2012 5:10 AM
    Subject: [NavList] Re: Extremely poor conditions??Atomic Clocks

    Alex and Bill,
    The two atomic clocks that I have used are an Oregon Scientific and a Seiko. Both have displayed a symbol when the synch signal is received. I am assuming then that synchronizing is taking place when ever this symbol is displayed. Each of the clock's have on occasion shown a one minute error with the synch signal symbol showing. I suspect that some type of local interference caused this but the true cause remains unknown. Each time the minutes were observed off (checked by shortwave time tick) the atomic clocks were manually reset to correct time to only reset automatically back to the one minute error again. Then a day or two later the correct time displays properly. This experience has ruined me for trusting atomic clocks or watches for serious celestial navigation experiments or for voyaging CN.
    Greg Rudzinski
    ] Re: Extremely poor conditions??
    From: Alexandre Eremenko
    Date: 22 Mar 2012 21:04
    Greg,
    I think my new reduction (message Atomic clock to the list)
    shows beyond any reasonable doubt that the clock was 1 min ahead.
    It only remains to understand how is such thing possible.
    (And then to convince Bill that it actually happened:-)
    It seems to me that an "atomic watch" is a usual quartz watch which is
    automatically adjusted by radio signans. How frequently?
    Now an ordinary quartz watch (non-atomic) will go away few seconds
    per YEAR. So how exactly this happens that an adjustment of such watch
    leads to 1 minute error? Can you describe the procedure of adjustment?
    I cannot imagine this procedure.

    Alex
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