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    Re: DosBox Tips
    From: Frank Reed
    Date: 2014 Feb 1, 11:52 -0800

    Greg, you wrote:
    "I too get a warm fuzzy feeling from seeing 'USNO' on the title page. I feel like; if they can't get it right, who can?"

    Sure, but this software is TWENTY-FIVE years old. Back then it was a major achievement, but today it's not only trivial, it is in fact flawed. Delta-T in ICE is currently wrong by about ten seconds. This is hardly the end of the world, but it is WRONG. "They" did not get it right, because they, very reasonably, made no provision for this software to be in use over two decades later. The only navigational impact of this flaw is that the position of the Moon is shifted consistently by 0.1 minutes of arc, but this will get worse with time.

    Creating software like this was once difficult. But no more. Here is my online Nautical Almanac data tool (which first became available TEN years ago):
    http://reednavigation.com/lunars/nadata_v5.html
    And here's the USNO web site version (a lineal descendant of ICE):
    http://aa.usno.navy.mil/data/docs/celnavtable.php
    Compare the GHA and Dec values for the Sun, Moon, and a couple of stars and planets for tomorrow. And compare against ICE, too.

    -FER


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