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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Sextant Positions versus Map Datums?
    From: Rodney Myrvaagnes
    Date: 2002 Jan 15, 12:49 PM

    On Tue, 15 Jan 2002 13:04:57 -0500, Jared Sherman wrote:
    
    >If NAD27 and WGS84 disagree by a mile, then wouldn't the "most accurate" 
    sextant position still either be off by a mile, or have been
    off by a mile? Or maybe still be off wherever the map datum doesn't match a "spherical earth" model?
    >
    
    AFIK, the difference between those two particular datums isn't big enough to 
    be detected in normal sextant use. The problem of
    horizontal chart errors is more likely to occur with charts surveyed in 
    isolation by Capt. Cook, for example.
    
    It only matters when you are on soundings. When you can see one of these 
    isolated islands it becomes piloting, whether you got there
    with a sextand, a cross-staff, dangling testicles, or a GPS.
    
    
    
    Rodney Myrvaagnes                   J36 Gjo/a
    
    "Religious wisdom is to wisdom as military music is to music."
    
    "What contemptible scoundrel stole the cork from my lunch?"  --  W. C Fields
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.
    Email:

    Email Settings

    NavList ID 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