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    Re: Cocked hats, again.
    From: Fred Hebard
    Date: 2007 Mar 15, 07:30 -0400

    Things like anomalous dip, fuzzy horizons, hazy sky, condition of the
    sextant operator, etc, will cause sigma to vary.
    On Mar 15, 2007, at 12:22 AM, Gary J. LaPook wrote:
    > Gary LaPook wrote:
    > Indeed I do assume that the sigma is the same for large and small
    > triangles. Sigma is based on the method of observation and the
    > randomness of the factors that effect the observations, waves, hazy
    > horizon, etc.
    > Sometimes the random errors have the same sign and you get a large
    > triangle and sometimes the signs are different and you get a smaller
    > triangle, this is the nature of random errors even though sigma
    > remains
    > the same.
    > Fred Hebard wrote:
    >> Gary,
    >> The size of the Gaussian bell curve, or whatever curve, around each
    >> position line wouldn't affect the probability of being on one side or
    >> another; as long as the curve is symmetrical the probability would
    >> still be one half.  The triangle is merely at the intersection of the
    >> lines; another of our assumptions are that the errors for each line
    >> are independent (and, for some calculations, equal).  A small
    >> triangle suggests that sigma is small for each line, and a large
    >> triangle that sigma is large.  You appear to be assuming sigma is the
    >> same size for different sized triangles.
    > >
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