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    Re: Linear regression and other tools
    From: Ron Jones
    Date: 2018 Oct 13, 17:45 -0700

    The length of time prior to or after meridian transit that the rate of change in the altitude of a body can be considered linear is strongly influnced by the difference in the bodies declinaltion and the latitude of the observer.  For example on October 13 2018 when the Sun's declination is approximately 8 deg. South,  consider the Sun's altitude vs time as viewed from latitudes 10N, 20N, 40N, 60N & 80N (see attached PDFs).

    Ron      48N   123W

    File:
    10N-Hc-of-Sun-vs-time.pdf
    File:
    20N-Hc-of-Sun-vs-time.pdf
    File:
    40N-Hc-of-Sun-vs-time.pdf
    File:
    60N-Hc-of-Sun-vs-Time.pdf
    File:
    80N-Hc-of-Sun-vs-time.pdf
       
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