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    Re: Celestial Navigation Data from USNO--alternative
    From: Dave Walden
    Date: 2019 Nov 30, 06:49 -0800

    The attached plot shows results that agree with Pauls, including the slope.  It makes the same assumptions and used the same JPL data as his, but is based on USNO NOVAs vs IAU SOFA routines as Pauls is (they should and have been shown to give the same results). 

    As he points out, one's answer depends on the delta T extrapolation used.  Paul used his.  The 2020, 2030, 2040 is based on "hemel.waarmemen.com/Computing".  Astron uses another.  Frank apparently another.  Ruiz may just assume constant delta T from current date.

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