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    Re: No Lunars Era
    From: Alexandre Eremenko
    Date: 2004 Dec 6, 21:30 -0500

    On Mon, 6 Dec 2004, Frank Reed wrote:
    > I can get lunars
    > accurate to 0.2 to 0.3 minutes on a regular basis
    I also can sometimes:-) But unfortunately not on the "regular basis".
    > Alex wrote:
    >> "My conclusion is that I am reasonably confident in 1'
    >>  accuracy (of the
    >>  distance) but not much better.
    >>  Some of my lunars are 0.6 and  even 0.7 off."
    > But those occur under specific circumstances, right?
    > Large angles, and
    > always positive error, right?
    Always positive, but sometimes 0.1, sometimes 0.3 and sometimes,
    unfortunately, 0.6. It is always a "systematic error",
    I mean that the variation of the error in a series of 5-10
    distances are small (about 0.2).
    > This
    > should be telling you something.
    That's why I am discussing refraction, irradiation and collimation
    all the time:-)
    > Or, accept it as an error of unknown
    > origin and subtract that amount as an instrument error
    It does not ALWAYS occur. I already posted some nearly perfect
    lunars, and have more.
    > Or, avoid those angles! As noted above,
    > navigators limited themselves
    > to  certain angular ranges in the great majority of cases.
    Well, I do not do this for my living:-) Why should I avoid angles?
    I do just the opposite: try to measure angles as large as possible.

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