Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Extremely poor conditions??
    From: Bill B
    Date: 2012 Mar 22, 19:38 -0400

    On 3/21/2012 5:36 PM, Alexandre E Eremenko wrote:
    > Greg,
    >> I have had two different digital atomic clocks jump a complete
    >> minute on me out of the blue for no reason.
    > Are you serious...  But Bill was comparing. (All electronic toys,
    > except a Casio calculator are his).
    >> I still think you are a minute out in your time rather
    >> than having a horizon 3.5 miles away elevated 11 moa.
    As I write to Alex: "Spring break on a beach in Michigan in winter. 80+
    F and people in swimsuits and swimming. If you can believe that, 10'
    ought to be a easy!
    I have two "clam shell" clocks (folds up like a travel clock). The first
    did a horrible job of picking up the time signal from Colorado, so i set
    it to UTC Zulu and to keep it next to my main computer to keep me honest.
    The second has been excellent.  It automatically polls Colorado about
    midnight.  I keep it facing CO on a three-seasons porch so it
    re-calibrates every day if needed. approached the list with the
    following question(s) about six years ago, but never really understood
    the "why" despite mentions of satellites corrections for gravity wells etc.
    The "atomic clock" (actually a clock that polls the atomic clock) is
    usually about a second different than my Garmin marine GPS, even when
    DUT1 is supposedly 0.  Why?
    (I have just checked the GPS against the clock at UTC 23:34:xx, and they
    are so close I cannot see a difference.  I will recheck right after the
    clock re-calibrate tonight.)
    A few side questions:
    Is Colorado transmitting UTC with leap second adjustments?
    Do satellites carry their own clocks, or are they synced up with CO and
    then making on board adjustments for speed/relativity and gravity well?
    Does GPS show UTC or UTC1 time?

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site