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: Lat/Long by Noon Sun
    From: George Huxtable
    Date: 2009 Apr 27, 23:51 +0100

    Gary LaPook had suggested that these pages-
    
    http://articles.adsabs.harvard.edu//full/1919PA.....27..359W/0000359.000.html
    http://articles.adsabs.harvard.edu//full/1919PA.....27..359W/0000363.000.html
    
    would be of interest in showing what could be achieved in measuring
    longitude-around-noon from equal-altitude observations of the Sun. However,
    I hadn't understood the point he was making. He answers-
    
    "Well I was impressed by the level of accuracy they achieved since it
    is much better than the 5 nm level of accuracy that has been discussed
    lately using sun sights around the time of noon."
    
    Ah! Now I follow, and fully agree with Gary. But really, it shouldn't be a
    surprise. It simply shows the precision that's obtainable when observations
    are taken at well-separated times, so that the Sun has very different
    azimuths, in the traditional way that mariners have always done such a job.
    And highlights the sacrifice in accuracy that results from trying to confine
    those observations to a short interval around noon. The contrast is
    instructive.
    
    George.
    
    contact George Huxtable, at  george{at}hux.me.uk
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    --~--~---------~--~----~------------~-------~--~----~
    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