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: Latitude and Longitude by "Noon Sun"
    From: Bill Noyce
    Date: 2005 Jun 7, 10:35 -0400

    There are courses taught to the spouses of private pilots, that
    teach the bare minimum needed to get the plane down safely if
    something happens to the pilot.  I see Frank's method of navigation
    by noon sights as the same kind of thing.
    
    The main argument in its favor is that it is easy to remember.
    If you were taught this method a few years ago and never used it,
    you could probably reconstruct it when called upon.  If you have
    any kind of mental picture of how the sun moves through the day
    and through the year, you can work out the logic of the sights.
    It can be done "by hand", with pencil and paper, without using
    any tables.  And the only almanac data you need is the sun's GP,
    tabulated perhaps once per day, and a rough value for dip and
    refraction (both small on a small boat in summer).  No need to
    remember the magic number 15.3, or a way to compute trig functions.
    You do need to remember that 1 minute of arc = 1 nautical mile,
    but that's about it.
    
    I would hope that students of this method also get told that there
    are more general methods, and a sketch of how they work, so they
    realize there's more that they haven't learned yet.  Really, the
    only added complication is computing Hc from an assumed position,
    so the noon sight, which might be easier to visualize, seems to me
    to make a good introduction.  Unfortunately, computing Hc requires
    more support -- either bulky tables, or a calculating device, or a
    longish pencil-and-paper procedure using short tables.  These are
    less likely to be available if the need for celestial navigation
    appears unexpectedly.
    
            -- Bill
    
    
    

       
    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