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: No DR position. How can you get an accurate celestial fix?
    From: Bill Lionheart
    Date: 2020 Jan 21, 11:43 +0000

    As the standard approach uses a linear approximation I have an idea if
    you start from any guess of the position and iterate this is
    equivalent to Newton's method for solving non-linear equations by
    successive linearization. Presumably there is a paper somewhere that
    says how close to the true position you have to be for convergence?
    On Mon, 20 Jan 2020 at 19:03, Dustin Baenen  wrote:
    > http://fer3.com/arc/m2.aspx/Can-I-Navigate-Without-an-Assumed-Position-Baenen-aug-2017-g39877
    > Here is a link from the 2017 thread mentioned earlier.  There is alot of 
    good info in it.  My amateur advice would be to start with your best guess of 
    a D/R (Last known fix, or just make one up like Moitessier did) and do 
    several iterations of your sight reduction using the resulting fix as a new 
    assumed position.  Within a few iterations the LOP's will stabalize around 
    your true position.
    > db
    > 44.30N, 88.00W
    > View and reply to this message

    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