Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
    Re: Astronomy: Calculating Positions
    From: Paul Hirose
    Date: 2008 Apr 07, 13:47 -0700

    I wrote:
    >
    > I have a free Windows positional astronomy DLL online which does these
    > things. There's also a C++ example which uses the DLL to compute
    > geocentric and topocentric positions of a star and the Moon.
    > http://home.earthlink.net/~s543t-24dst/sofajpl/lunardist.html
    
    There's a difference of several arc seconds between the sample run and
    the JPL HORIZONS online calculator. It's a time scale discrepancy. The
    sample run assumes values for (TT-UT1) and (UT1-UTC) which are
    significantly different from the actual values of date used by HORIZONS.
    
    The USNO MICA program will duplicate the sample run if you use the
    values of TT and the ephemeris longitude of the observer shown in the
    sample run output.
    
    I should change the parameters so the results match HORIZONS.
    
    --
    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
    -~----------~----~----~----~------~----~------~--~---
    
    

    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