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: On the Mischief of Geographical Position.
    From: Dave Weilacher
    Date: 2002 Jan 24, 1:10 PM

    ..It is the ZENITH distance...  Dave Weilacher did not write this.  Hebert Prinz did.
    I am too much of a simple minded, sometimes single handed, sailor, to put that much thought into it.
    I was arguing against the validity of it, is all.
    Dave Weilacher
    Original Message:
    From- Michael Wescott wescott_mike@EMC.COM
    Date: Thu, 24 Jan 2002 14:49:20 -0500
    Subject: Re: [NAV-L] On the Mischief of Geographical Position.
    daveweilacher@earthlink.net wrote:
    >> It is the
    >> ZENITH that the navigator is attempting to locate in the celestial
    >> sphere. Once that has been accomplished, he projects it down via the
    >> local vertical, simply by renaming declination latitude, and GHA
    >> longitude, and calls it his  position . This works on an egg, a pear, a
    >> lemon or an onion.
    Rodney Myrvaagnes  replies:
    > This is rigorously true, but it dodges the question that I think
    > people meant to ask, vis: If the local vertical (gravitationally
    > determined) doesn't point to the center of the earth or the celestial
    > sphere, then where is the position so measured?
    The actual (meaning the astronomical) latitude and longitude of a
    place is what is measured.  In other words, the position so measured
    is exactly that place where it is measured. Due to local gravitational
    anomalies there may even be other places nearby with the same
    astronomical latitude and longitude.
    mail2web - Check your email from the web at
    http://mail2web.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