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: Navigation without Leap Seconds
    From: Lu Abel
    Date: 2008 Apr 18, 09:10 -0700

    Geoffrey Kolbe wrote:
    > Well, my Long Term Almanac is nominally good up to the year 2050 and will
    > actually work OK up until 2060. So this is a very real question for me.
    > I am assuming that if leap seconds are abolished, anyone using my tables -
    > which assume GMT, or UT1 as it is called these days - will know the
    > difference between broadcast time and GMT and use this as a correction to
    > broadcast time.
    On the contrary, your long term almanac is based on the measurement of
    "what time is it" at some point in time (likely when it was published).
    So it does NOT correct for leap-seconds, since there is no way to
    predict when they will be inserted into UTC.   So it is effectively
    already practicing leap-second-less navigation.
    I don't know how old your long term almanac is, but if it's old enough
    it would be interesting to compare its data with current Nautical
    Almanac data; I'll bet there might be some small discrepancies in some
    GHA predictions.
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com

    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