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    Re: suggestion for a satisfactory celnav narrative
    From: Frank Reed CT
    Date: 2005 Jun 4, 20:42 EDT
    George H wrote:
    "But why, in this age, does a mariner still ask for separate determinations
    of latitude and longitude? It's as if we were still stuck in the early
    1800s, and Sumner and St Hilaire had never invented position lines."
    A little ironic, no?
    Why, in this age, does a mariner still ask how celestial navigation works? It's as if we were still stuck in the 1970s, and GPS has not been commercialized yet.
    Or how about this variant:
    Why, in this age, does a mariner still ask how lunar distance observations might work? It's as if we're still stuck...
    Well... you get the idea!
    "Why not just measure two altitudes of the Sun, at any old times, but times which
    are well separated so that the Sun's azimuth has changed significantly
    between them. Then draw a couple of position lines from some assumed
    position, allow for vessel's run in the interval, see where they cross, and
    that's where you are, in lat and long. Simple as that. Applies to any sight
    of any body at any time: a universal way of doing the job. Who needs
    anything different? "
    That's a ten-week course of work and frequent repetition required to keep up the skill. By contrast lat/lon by noon sun is something that can be learned and re-learned in an afternoon. It's not quite as accurate (does that matter? depends on what you're trying to achieve) as full-blown celestial navigation, but fewer and fewer students are interested in toiling over the details of the Nautical Almanac's interpolation tables and the tedious study of H.O. 229 or other sight reduction tables. They wanna play with their sextants and figure out where they are in the fewest possible steps (just in case something bad happens to GPS). Of course, there are still plenty of others who want to learn the complete methods of "apex celestial navigation" because that suits their personal goals and interests. We're even getting to the point where people are studying it out of historical interest...
    42.0N 87.7W, or 41.4N 72.1W.
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