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    Re: Precision of lunars
    From: Fred Hebard
    Date: 2007 Apr 19, 16:52 -0400

    Old list. Dec 2003, Jan 2004.  Maybe Nov 2003.
    On Apr 19, 2007, at 4:10 PM, Alexandre E Eremenko wrote:
    > Dear Fred,
    > Thanks for your encouraging message.
    >> Your findings also dovetail with Jan
    >> Kalivoda's report of the findings of a German who investigated
    >> precision of lunars at sea in the late 1800s.
    > Can this be found? Was this on the old list or on a new one?
    >> standard deviation of lunar distance reported by Jan was about 25
    >> arcseconds.
    > That is 0'.4. I am very interested, how exactly this was studied.
    >> I am wondering how much practice you estimate it took you to achieve
    >> this level of proficiency?
    > Probably several thousands individual shots (star-to-star and Lunar
    > distances). 4 standard student notebooks of records.
    > And a lot of thinking about the reasons of errors.
    > I am constantly doing this for about 3 years, since I bought my
    > SNO-T. I mean almost every evening with clear sky...
    > well perhaps 1/2 of all evenings with clear sky:-)
    > I reported my results from time to time, good and bad.
    > From the very beginning I had occasionaly very good results,
    > but some were bad.
    > And this was unpredictable. Gradually the proportion of good results
    > increased... by 2007 it increased to a reasonable level:-)
    > Right now I looked into the records of a year ago.
    > About 1/2 of all shots were within 0'.3 limit
    > and another half 0'.4-1'. Some had even more than 1',
    > but these were not frequent.
    > I used to blame my sextant...
    > Now it is much better. And I think that the sextant is very good
    > after all.
    > Alex.
    > >
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