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: Still on LOP's (mea culpa)
    From: Rodney Myrvaagnes
    Date: 2002 Apr 26, 07:49 -0500

    Now I am getting confused anew. If the sigma is the same for each LOP,
    then how can the expression below weight dN differently from dM. All
    the d's are squared inside the exp(). So in a 3-LOP case, how could the
    center be anything but the center of the inscribed circle (i.e. all d
    the same value)?
    Plainly when more than 3 LOPs are in play, it is no longer an inscribed
    anything, so I guess the distinction is an accidental case, rather than
    anything fundamental.
    On Fri, 26 Apr 2002 00:48:07 -0400, Michael Wescott wrote:
    >Given that each observation comes from the same Gaussian distribution
    >the joint probability density is proportional to
    >        exp( -(d1**2 + d2**2 + d3**2 ... ))
    >where dn is the distance from a point to LOP number n. So it's
    >a matter of minimizing d1**2 + d2**2 + d3**2 ...  to get maximum
    >joint prob density or MPP. In other words it's a least squares problem.
    >So Steven Tripp, Trevor Kenchington et al. were correct that the MPP is
    >not the center of the inscribed circle.
    Rodney Myrvaagnes                                  J36 Gjo/a
    "Curse thee, thou quadrant. No longer will I guide my earthly way by thee."  Capt. Ahab

    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