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: Digital Camera Celestial Navigation
    From: Paul Hirose
    Date: 2008 Jul 09, 09:10 -0700

    Marcel Tschudin wrote:
    > Paul wrote:
    > "With a body of 16' semidiameter, and sea level refraction, this
    > decreases the semidiameter about .27". I tested this at several
    > altitudes from 10 degrees to 80, and it didn't vary more than .01[sec
    > arc]".
    > I couldn't figure out how you obtained this value. Looking at it
    > geometrically by linear interpolation: about 0.5 deg refraction at the
    > horizon and 0 refraction in zenith direction results in a much larger
    > value. Looking at it using differential refraction shouldn't result in
    > a more or less constant value (0.27"). I would appreciate if you could
    > explain the cause of the effect in more detail.
    
    Your values are the vertical refraction. My message was about the
    decrease in *horizontal* semidiameter due to refraction.
    
    --
    I block messages that contain attachments or HTML.
    
    --~--~---------~--~----~------------~-------~--~----~
    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