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: First Moon-Star Lunar
    From: Ed Popko
    Date: 2017 Dec 31, 03:44 -0800

    Kermit, Sean, Frank:

    In my note to Sean [1], I use my HP calculator program version and input Sean's altitude corrections for moon and Aldebaran rather than mine. Sean used NA published equations to compute them, I used the NA tables to look them up.

    After using Sean's altitude correction values [2], I get the same A, B and cleared lunar values as he does but our Q values differed a lot. Both our Q values were very small and seemed not to have affected our final cleared lunar value. 

    But, why such difference computed Q values?  When I comparing Sean's Q equation with my calculator equation, I find that I had used

    the ATAN function rather than COTAN as he did.  I changed ATAN to COTAN and reran:

          Q = .55*ACm^2*(1./TAN(LDpc))*(1.0-A^2)/3438.  Where x^2 denotes squared and COTAN is 1./TAN(x) 

    Our values for A, B, Q and final cleared lunar now agree completely.

    I am having a small vacation and do not have access to my notes from Frank's lunars workshop. I'm curous as to why I used ATAN rather than COTAN in my Q equation. But even with ATAN, many other lunars test cases agree very well with results published elsewhere but computed by different methods. 

    Ed

    ------------------------------------------------------------------------------------------------------------------------

    [1] fer3.com/arc/m2.aspx/First-MoonStar-Lunar-EdPopko-dec-2017-g41062

    [2] fer3.com/arc/m2.aspx/First-MoonStar-Lunar-SeanC-dec-2017-g41056

       
    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