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Frank wrote-
|
| I don't have time to answer this in detail today, George, but I am so
sorry
| that this is causing you so much 'angst'. It's really a very simple thing,
| and I must have somehow missed a few of these questions which you claim
I'm
| evading (a few I have ignored because they seem so bizarre to me). Really,
I
| am sorry you're so frustrated, and I will try to help you with your
| understanding.

Frank is being most solicitous, but there is no failure of understanding.
It's a failure of communication. Frank insists that he can achieve an
overall standard deviation of 6 miles, partly by averaging several
observations. I have asked him to estimate what the various observation
errors are, in two categories; those that vary randomly, that can be
improved by repetition, and the systematic errors that can not. Those are
the questions that await answers.

If he considers that error from a particular source is zero, such as (for
example) that from abnormal refraction, he can simply say so, not take
offence that the question is being asked. It may well be a fair enough
assumption that horizontal gradients of temperature and pressure have a
negligible effect, and I wouldn't argue with it. Of special interest is his
assessment of the calibration error of his sextant, along its arc, and what
that assessment is based on.

Until we can see how these various errors might add up, we have no way to
decide whether his 6 mile claim is a reasonable one, or not.

George.

contact George Huxtable at george@huxtable.u-net.com
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.


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