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: sextants on aeroplanes
    From: Jeremy C
    Date: 2008 Dec 13, 04:58 EST
    Snip
     
     
    Sextants and quadrants allow a greater
    range of measurement which might be useful for lunar distance
    measurements, horizontal sextant angles for coast wise navigation and in
    the rare case of a body within 30º of the zenith with an obstructed
    horizon below it but a clear horizon in the opposite direction in which
    case the navigator could turn his back to the star and use the opposing
    horizon for the sight. (I don't know if this was ever actually done in
    real life.)
     
    --------------------------------------------------
     
    This has been done in practice at sea.  I have done it several times in the tropics when the sun is high.  Typically because at the regular azimuth there is a thunderstorm that obscures or muddles the true horizon but there is a perfectly good horizon 180 degrees out.  Shoot a backsight, and you are good to go; as long as you remember how to do it.  It is also in the US Coast Guard tests, but mostly as Hs to Ho reductions.
     
    Jeremy




    --~--~---------~--~----~------------~-------~--~----~
    Navigation List archive: www.fer3.com/arc
    To post, email 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