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Re: Anomalous dip. was: [NAV-L] Testing pocket sextant.

From: Alexandre E Eremenko (no email)
Date: Sat Jun 17 2006 - 04:32:03 EDT

  • Next message: Peter Fogg: "Re: Anomalous dip"

    Bill,

    > Next, I envy your ability to keep things straight when dealing with signs
    > that are (to me) all but arbitrary in many cases. Words do seem to get in
    > the way. Is "towards the body" plus and "away from the body" negative?
    > Perhaps anchored to how one first learned.

    I agree. Dealing with signs is tricky, and frequently causes blunders.
    (As recent examples, I mention the discussion of the dip,
    which way the temperature gradient near the surface distorts the dip,
    and "error in longitude" in Frank's Lunar calculator.
    See, even Frank, who always has correct answers to
    almost everything, sometimes can have the
    sign wrong:-)

    It is even worse with azimuth:-)
    I remember the horrible rules from the Russian manual
    for determining the aimuth (in "quarter count") from
    the reduction formulas. It was much easier to
    glance at a compas and record in which quarter your
    celestial body was during the observation, than to
    apply these rules:-)

    > Looking forward to your "sea trials" and photos,

    1. I have no camera.
    2. I am pessimistic about weather.
    It seems that unfortunately Kiel has already received
    its full portion of sunny days for this summer last week:-(
    Perhaps it is not so cloudy in Denmark...

    Alex.


  • Next message: Peter Fogg: "Re: Anomalous dip"



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