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
    Prime Meridian on the move
    From: Peter Monta
    Date: 2016 Jan 15, 07:06 -0800
    GPS World has a brief discussion of the Greenwich Meridian by the authors of the recent paper on its history and relationship to the ITRF:


    Incidentally, does anyone know the status of any effort to make a small auxiliary tourist exhibit at the ITRF meridian?  They really should.  I was at Greenwich about five years ago, and did the obligatory 100-meter walk east, but there was nothing but grass and an asphalt footpath.


    - brass survey disk (with suitable monument) at the ITRF meridian with explanatory plaque
    - small fixed telescope pointing downward, looking toward an illuminated target at ground level.  "This way to center of Earth."  The DoV might be too small to show clearly, though.
    - careful survey of the tourist line and the new monument, good to a centimeter or so.  This would take only a couple of hours with a survey-grade GNSS receiver and a total station.  No need to set up on the tourist line itself---it can all be done with a few setups on the open areas nearby with intervisibility to the tourist line and the new monument.


    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