Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: (Graphical) haversine way of clearing the lunar distance
    From: Frank Reed
    Date: 2015 Nov 13, 09:55 -0800

    Jaap, there seems to be some confusion here. You wrote:
    "why is using the haversine formula proposed earlier the worst possible way to go when one would decide to clear the lunar distance by longhand calculation?"

    Did I misunderstand you? You made it very clear in your original message that this would involve a long division and therefore it was highly impractical for longhand calculation. I added my comment only because I felt your follow-up, spelling out the calculation in detail, obscured that earlier, very important point, and, knowing some of our NavList readers as I do very well, that point was bound to get lost. You were right that this is a highly impractical way to clear lunars. These intriguing diagram solutions which you have been exploring have some applications in celestial navigation, but only when the necessary precision in the computation is rather low. There are, of course, methods for clearing lunars that work with lower precision calculating techniques: the series methods, which I have recommended multiple times. The "corner cosines" (cosines of the position angles ZMS and ZSM) are required only to a few digits precision in the series methods. 

    Frank Reed

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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