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
    New Scientist: GPS mystery is making ships appear to teleport and move in circles
    From: Paul Saffo
    Date: 2020 Dec 12, 14:48 -0800

    I wonder why all the signals are pointing to Pt. Reyes. Might it have something to do with that Utah monolith? ;-)

    https://www.newscientist.com/article/2245305-gps-mystery-is-making-ships-appear-to-teleport-and-move-in-circles/#ixzz6gS7v3UyH

    GPS mystery is making ships appear to teleport and move in circles

    TECHNOLOGY 4 June 2020
    By  David Hambling

    Ships around the world are reporting false locations, seeming to circle Point Reyes near San Francisco when they are actually thousands of kilometres away.

    The locations are broadcast by each ship’s Automatic Identification System (AIS). These are required under international law to signal a vessel’s identity and GPS location. Bjorn Bergman of the environmental watchdogs SkyTruth and Global Fishing Watch discovered the anomalies from a historical database of AIS information.
    Bergman was tipped off when he noticed records from 2018 and 2019 of satellites receiving AIS locations outside areas they cover, for example, a satellite over West Africa picking up a ship supposedly off California. Vessels affected included a livestock carrier near Libya, a cargo ship in the Suez Canal, a small boat off Chile and a Norwegian tug.
    (snip)

       
    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