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    Re: Still on LOP's (mea culpa)
    From: Michael Wescott
    Date: 2002 Apr 26, 00:48 -0400

    I wrote:
    > Sorry, but Steven Tripp's calculations don't find the MPP. They find
    > the least squares point, a computationally more tractable exercise and
    > in this case, they aren't the same.
    And I was wrong.
    So much for my credentials ...
    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.
    I still wonder what the Nautical Almanac meant in that article ...
            Mike Wescott

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