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    Re: Berson's Noon Sun problem
    From: Frank Reed
    Date: 2013 Feb 12, 10:37 -0800

    Robin, you wrote:
    "The ON result for latitude is quite a bit different from both what I get with the Nautical Almanac and from Frank’s 25d14.6’N using 19th century methods."

    And, by the way, I agree with your result, 25d 14.3', from the standard Nautical Almanac tables (the "true" number might be a tenth different from that). It is indeed amazing that Berson's published answer could be so poor. Clearly they're missing that most important element of quality control: a technically competent proofreader.

    And you wrote:
    "Given the ON answers above you can work backwards to find what value of the Sun’s declination of the must have been used. This comes out be 8d55.9’N which is exactly the declination listed in the Almanac for 12h GMT. Coincidence?"

    Unfortunately, that's probably just what was done. It's an interesting phenomenon. He goes to all the trouble of calculating the GMT of Local Apparent Noon, but then he doesn't use it correctly.

    And you wrote:
    "Unfortunately over the limited period that I have been subscribing to Ocean Navigator errors of one type or another don’t appear to be very uncommon. The November/December 2012 edition contains a problem in which a value of Hs of 38d28.8’ yields a value for Ho of 21d46.7’."

    Must be anomalous refraction!

    And you concluded:
    "If I had a point it would be that I find it rather sad that one of the few readily available sources Celnav problems can be have these sorts of issues. It must be discouraging for those trying to use them to learn the practice."

    Yes. And its's worse that they do not publish corrections of their errors. Well, with any luck, those discouraged beginners will make their way to NavList...

    -FER


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