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    Re: Nautical Almanac
    From: Sean C
    Date: 2018 Aug 11, 17:52 -0700

    Paul,

    You wrote:

    "A disadvantage of MICA is that it displays zenith distance, not altitude. Also, MICA doesn't apply refraction. The only angle formats available are decimal degrees or degrees minutes seconds. Fortunately it's no great challenge to mentally convert seconds to tenths of minutes."

    Yes, and there are other disadvantages for those using MICA for celestial navigation purposes. For instance: geocentric coordinates referenced to the equator are displayed in R.A. only, requiring the user to also calculate sidereal time in order to convert to GHA or LHA. And, MICA's estimate of Delta-T is currently 0.8 seconds greater than the actual value. An option for user-defined Delta-T values would be nice. (This is actually possible when calculating eclipses and transits, but nowhere else.)  There are other minor inconveniences I've run into, but none spring to mind just now. In many ways, MICA was an improvement over its predecessor, the Interactive Computer Ephemeris or ICE. But in some ways, I preferred ICE.

    Speaking of MICA's Delta-T inaccuracy, I wonder when they are going to update the file.

       
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