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    Re: Astronomical Refraction: Computational Method for All Zenith Angles
    From: Marcel Tschudin
    Date: 2005 Aug 22, 12:13 +0300

    Wasn't connected to the Internet during this weekend. Thought it would be
    the provider as it happens here occasionally, but this time it was on my
    side, a bad contact in the plug of the telephone line ...
    In the meantime I programmed the density profile, you, Frank, proposed. I
    see that there is still a more refined proposition in calculating the
    densities by using the lapse rate of the standard atmosphere where one even
    could introduce a modelled inversion.
    But before going ahead using other atmospheric models, I really wanted to
    validate the program itself by reproducing the values shown in the Auer
    Standish paper, where they compare their results to analytical data and
    achieve a one to one correspondence for the zenith angles between 15deg and
    60deg. But unfortunately I was not able to reproduce these values to the
    same accuracy level. Even introducing Simpson integration did not help.
    Thought then that it could be due to an other misprint of one of the input
    data. But also varying the input data, it is just not possible to achieve
    the results in an accuracy level as shown. I am therefore wandering what
    either they or we might have done different to what they describe in their
    P.S: Actually the second paper from Garfinkel (1967) contains also some
    benchmarks for zenith angles between 85deg and 90deg.

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