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: instances of the use of "horizon grazing" technique
    From: Greg Rudzinski
    Date: 2009 Oct 6, 16:01 -0700

    John,
    
    The technique that you are describing sounds like latitude by upper/
    lower transit of a star. Stars are hard to see near the horizon which
    means that the transit should be more than 5� above the horizon. The
    altitude can be approximated by finger widths (rule of finger) of an
    outstretched hand. My finger widths are about 1�45' so that four
    fingers gives a 7� measure of arc. Haven't tried the finger rule for
    celestial purposes but have had luck in piloting applications such as
    doubling the angle on the bow and wether another sailboat is gaining
    or retreating by measuring the vertical angle of the mast head.
    
    Greg
    
    On Oct 6, 10:36�am, Apache Runner  wrote:
    > A number of emergency navigation sources talk about finding (very rough)
    > latitude by looking at the minimum altitude of horizon grazing stars. � �I'm
    > unaware of anyone that has actually used this technique, but perhaps someone
    > has used it in a real (as opposed to trial) situation. � Any anecdotes or
    > historical citations of this being used?
    >
    > John Huth
    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To unsubscribe, email NavList+unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    

       
    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