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    Re: Instumental error?
    From: Frank Reed CT
    Date: 2005 Apr 21, 23:37 EDT

    Fred you wrote:
    "Sun-moon lunars are still giving me fits, whereas I've had some  nice
    ones with Jupiter. "
    That's very odd. Maybe there's more  irradiation in the water where you live.
    Are you in a high Irradon area??  :-)
    And wrote:
    "Another problem I've had with lunars is that I was using  what I thought
    was a faithful representation of Young's method of clearing,  as put
    forth by Geo. Huxtable.  It doesn't give the same results as  Frank
    Reed's lunars page, usually giving cleared distances about 0.3' of  arc
    away from Frank's. "
    Don't forget, there *was* a bug in my  calculator last fall (I didn't realize
    so many people were using it so I was  modifying with it rather casually).
    Regardless, this clearing process is really  not a difficult calculation and
    there shouldn't be any problem with it. If you  don't shoot the altitudes along
    with the lunar distance, I think it's important  to emphasize that the
    additional calculation of the altitudes introduces an  extra layer of potential error.
    Incidentally, this idea that there is a  "Young's method" I think is way
    over-sold by Cotter's book. It's a minor  modification of the basic triangle
    solution which has been understood for  centuries. The "basic triangle solution" is
    two lines of work  followed by a "voila" in Mendoza y Rios's paper in the
    Transactions of the Royal  Society in 1797.
    42.0N 87.7W, or 41.4N  72.1W.

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