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    Re: Lat/Lon by "Noon Sun" & The Noon Fix PROVE IT
    From: Peter Hakel
    Date: 2009 Apr 23, 16:47 -0700
    Try OpenOffice or NeoOffice.    Peter


    From: Hewitt Schlereth <hhew36---.com>
    To: NavList@fer3.com
    Sent: Thursday, April 23, 2009 2:59:27 PM
    Subject: [NavList 8027] Re: Lat/Lon by "Noon Sun" & The Noon Fix PROVE IT


    George, I have a Mac iBook and it doesn't have a spread-sheet program.
    Pressing F9 does absolutely nothing.

    The AppleWorks program did open your "long around noon.xls"
    attachment. What I was presented with  looked much like a ledger page.

    The altitudes I used for figuring longitude were from the "perturbed
    alt" row on that page. They were nearly equal - i.e.,10.812 at 1210,
    10.815 at 1250.

    The altitude for latitude was from the same "perturbed alt" row -
    10.914 at 1230.

    Hewitt

    On 4/23/09, George Huxtable <george{at}hux.me.uk> wrote:
    > Hewitt Schlereth wrote-
    >
    >
    >  | George, it looks like I may have misunderstood the document I got the
    >  | (nearly) equal AM/PM altitudes from. I thought it was your spreadsheet
    >  | and cited it's designation - LONG AROUND NOON.XLS (SS) - in the
    >  | worksheet I attached to my e-mail. The numbers I used were from that
    >  | document - which I took to be yours. They looked mighty like sextant
    >  | altitudes; so, certainly not random numbers generated by me.
    >  |
    >  | Maybe my worksheet didn't come through to the List?  Here it is again.
    >
    >  ==================
    >
    >
    > Hewitt and I have got ourselves at cross-purposes, it seems.
    >
    >  I had produced 20 simulated sets of "perturbed" sextant altitudes, each of
    >  13 observations taken at regular intervals around noon. These were offered
    >  so that list-members could analyse them in any way they chose, to try to
    >  discover the original latitudes and longitudes on which they were based,
    >  information which I withheld. The table was attached to [7940] as
    >
    > noon1a.rtf, or (the same data), attached to [7959], as noon1a.doc .
    >
    >
    > In case anyone wanted to see how that data had been generated, I also added
    >  the Excel spreadsheet, that generated those data sets.. Each time that
    >  spreadsheet is run, (or when button F9 is pressed), a new set of random
    >  numbers is generated, which creates a new, unique set of perturbed
    >  altitudes. I hadn't intended anyone to use that spreadsheet itself to
    >  generate those sets of altitudes, but there's nothing wrong with doing so;
    >  indeed, that's what Dave Walden did, generating 1000 such sets to look for
    >  the scatter.
    >
    >  Hewitt has done the same, but has generated only one such data-set, which
    >  has given an answer which Hewitt tells is is within 1' of the intial value.
    >  To which I suggest that if that is the case, it's only so as the result of a
    >  fluke, and will not be repeatable.
    >
    >  If Hewitt will kindly load and run that Excel program again, it will invent,
    >  this time, a completely new set of 13 altitudes, showing a similar general
    >  shape but differing in every detail. And if he analyses the new set as he
    >  did before, he will, I suggest, get a very different answer. Every time he
    >  presses F9, it will change again.
    >
    >  However, having satisfied himself on that score, he could usefully apply
    >  whatever technique he chooses, to one or more of the data sets attached to
    >  those messages cited above, also attached here. The first two sets, only,
    >  provide that original data. For the other 18, only I know the original lat
    >  and long from which the data set has been constructed.
    >
    >
    >  George.
    >
    >  contact George Huxtable, at  george{at}hux.me.uk
    >  or at +44 1865 820222 (from UK, 01865 820222)
    >  or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    >
    >  >
    >
    >


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