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    Re: Lunar distance accuracy
    From: Alexandre Eremenko
    Date: 2007 Oct 22, 13:37 -0400

    
    Jim,
    Let me briefly summarize what I know about Lunars
    accuracy.
    
    1. Expert's opinions (Lecky, Kelvin, Frank)
    None of these authorities cites any data of specific
    observations.
    
    2. My own statistics of Cook's expedition observations
    from the known point (Point Venus in Thaiti).
    This I posted in a series of messages on this list
    last spring.
    
    3. Few observations of some land surveyors of XIX century
    posted on this list, but the exact position from which these
    observations were made is not always known.
    
    4. Research of a German navigator in 1890-s;
    unfortunately his observations were made in a sea voyage,
    so the precise position of his observations was not known.
    I can post his papers if someone is interested, but they
    are in German.
    
    5. My own observations during the last 3 years from
    one exactly known position, and some sea observations
    controlled by GPS. Many of them are posted on the list
    but I have much more.
    
    These are all data I have. I will be very grateful if some
    one points to any other hard data or research on the subject.
    
    Alex.
    
    On Mon, 22 Oct 2007, Jim wrote:
    
    >
    >
    > Lunar distance accuracy
    >
    > Looking for some qualitative comments regarding the accuracy of lunar
    > distances. I have been looking through the archives and not found
    > quite what I am looking for.
    >
    > I have not had the time patience and discipline to carefully log my
    > observations but, I have noticed that the sun moon lunars seem to be
    > more accurate than star moon lunars which are in turn better than the
    > planet moon lunars.
    >
    > Standing on land in good conditions, no averaging, I have found that
    > obtaining sun moon lunars with an accuracy of <0.5' can be obtained
    > routinely with many sights well within this. Using stars I would have
    > to estimate a slight increase in error putting it at <0.7'. Using
    > planets I find that getting reliable results consistently <1.0' is
    > getting to be a challenge.
    >
    > Have others had the same experience? Again, not looking for a detailed
    > statistical analysis but more qualitative comments.
    >
    >
    > >
    
    
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