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: Sextant Accuracy
    From: Bruce Stark
    Date: 2003 Mar 17, 11:48 EST

    Fred,
    
    Supposing you're bringing the lower limb of the sun to the upper edge of the
    reflection in the water, a visual phenomenon called "irradiation" could put
    you north of the truth. Irradiation makes a bright object seem bigger than it
    really is. When I measure the sun's diameter on and off the arc to check
    index correction, the average of the measurements is always greater than the
    true diameter of the sun.
    
    Bruce
    
    
    

       
    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