Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: GPS as a time authority
    From: Lu Abel
    Date: 2009 Sep 14, 20:45 -0700

    The problem with the accuracy of GPS time displays is usually due to the 
    time it takes for them to internally process the data and display it.  
    This can take several seconds (although I've never heard of >5 seconds), 
    especially on older GPS units with non-multichannel receivers and slow 
    microprocessors.   All this leads to the GPS display being slow.   If 
    anyone on this list has experience with a GPS display being fast, that 
    would be worth noting.
    
    JKP@obec.com wrote:
    > I think this has been dicussed before, but I'd like to be refreshed on the list's opinion:
    >
    > While assisting the Race Committee at a regatta this weekend, I heard the 
    timekeepers say that they were using "GPS time."  I noted that my $79 
    wristwatch, which I check monthly against the US Bureau of Standards atomic 
    clock (ph: 303-499-7111) and which doesn't lose a second per month, was 8 
    seconds ahead of the Committee's time.
    >
    > I later checked the time shown on my hand-held Gartmin GPS receiver, and it 
    agreed with my watch.  The watch was also still in sync with the Bureau's 
    atomic clock.
    >
    > Question:  Is the time displayed by GPS receivers considered a reliable and 
    spot-on source, up to the requirements of accurate celnav?  I would think 
    that it would be, since the GPS network depends on accurate tracking of the 
    satellites' position at a given time, yet there was that 8-second 
    discrepancy.  Perhaps the Race Committee were simply careless about setting 
    theior clockby GPS.
    >
    > Any thoughts, List Members?
    >
    > -John Parsons
    >
    >
    > >
    >   
    
    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    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