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: The Darn Old Cocked Hat - the sequel 1
    From: Gary LaPook
    Date: 2013 Mar 13, 16:00 -0700
    I am attaching the treatment of dispersion of artillery shells from FM 6-40, 1999 ed.


    --- On Wed, 3/13/13, Geoffrey Kolbe <geoffreykolbe---.com> wrote:

    From: Geoffrey Kolbe <geoffreykolbe---.com>
    Subject: [NavList] Re: The Darn Old Cocked Hat - the sequel 1
    To: garylapook---.net
    Date: Wednesday, March 13, 2013, 12:04 PM


    I don't buy your maths. The problem you outline in your two 'papers' is very similar to the statistical distribution of the fall of shot at a target. The standard work on that is "Statistical Measures of Accuracy for Riflemen and Missile Engineers" by Frank E Grubbs. It was self published in 1964, but is still the seminal and most cited work on this subject. I suggest you glance in that work to see how your subject should be treated. I should add that ammunition factories around the world shoot millions of rounds of ammo every day and measure the quality of their ammo using the statistical techniques laid out in Grubbs' monograph. If Grubbs was wrong, we would know about it!


    You said:
    "Compare the Goudsmit result of the true shipâs position being outside the hat 75% of the time, with the symmedian result. They are both correct results to two different questions (but only the last one is relevant for CN). It requires some intriguing thought to see why this is true."

    Actually, the Goudsmit result can be achieved by averaging over the entire grand canonical ensemble of possible cocked hats within the probability distribution you describe, as was done by somebody using Monte Carlo methods (I forget who) the last time we went through this. The two approaches are equivalent.

    Geoffrey Kolbe

    View and reply to this message: http://fer3.com/arc/m2.aspx?i=122846



    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