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    Re: Averaging
    From: Alexandre Eremenko
    Date: 2004 Nov 5, 22:25 -0500

    Dear Herbert,
    I am beginning to suspect that we are just
    talking about different things.
    
    I repeat the setting.
    We were discussing, say 3 observations of ONE
    body's altitude, spread over 5 minutes. You cannot obtain
    a FIX from these data. This will be a VERY BAD fix
    if you try. To obtain a fix from one body altitudes
    you have to SPREAD your observations in time, so that
    the azymuth changes MUCH.
    
    From 3 observations spread over 5 minutes you can
    obtain ONE position line. Not a fix.
    
    On Fri, 5 Nov 2004, Herbert Prinz wrote:
    
    > I want nothing of the sort. As I said, my equation M * x = a refers to any
    > system of linear equations.  In the problem in hand, these represent LOPs
    > and the solution of the system is the FIX.
    
    > Have you actually looked at the algorithm in the N.A.?
    > Have you looked at
    > the articles in the Navigation Journal? That's what I am proposing.
    
    Unfortunately, I do not have access to this journal.
    And from your messages I cannot determine what situation is
    really described in these papers.
    
    Alex.
    
    P.S. Maybe they are talking about observing more than two bodies,
    say 3 stars, and how to make a fix from such observations?
    I don't think least squares are really needed in this situation,
    but certainly people who like computers and do not like
    drawing can do this.
    But this is a totally different situation from what I was talking
    about. I was talking all the time of ONE body
    observations over SHORT
    time. I never proposed averaging anything else:-)
    
    
    

       
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