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 Image CN Exercise
    From: Marcel Tschudin
    Date: 2010 Apr 9, 09:43 +0300

    Thank you, Wolfgang for the code snippet.
    
    The program from Mr. Umland is for use in CN. It uses Bennett's
    formula for calculating the refraction from the observed *apparent*
    altitude in order to obtain true altitude. I solve this problem with
    my positional astronomy program differently, the other way round. I do
    this by first calculating the sun's position in topocentric,
    astrometric coordinates providing the *true* altitude which then, by
    adding refraction, is converted to apparent altitude. The solution is
    then found iteratively until the calculated apparent altitude agrees
    with the observed one. A different refraction formulae has to be used
    for each of the two cases.
    
    Marcel
    
    
    
    

       
    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