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  2. Longitude by chronometer - Wikipedia

    en.wikipedia.org/wiki/Longitude_by_chronometer

    Time sight is a general method for determining longitude by celestial observations using a chronometer; these observations are reduced by solving the navigational triangle for meridian angle and require known values for altitude, latitude, and declination; the meridian angle is converted to local hour angle and compared with Greenwich hour angle.

  3. Longitude - Wikipedia

    en.wikipedia.org/wiki/Longitude

    Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absolute measure of time allows longitude to be determined. Depending on the era, the absolute time might be obtained from a ...

  4. History of longitude - Wikipedia

    en.wikipedia.org/wiki/History_of_longitude

    Longitude calculations can be simplified using a clock is set to the local time of a starting point whose longitude is known, transporting it to a new location, and using it for astronomical observations. The longitude of the new location can be determined by comparing the difference of local mean time and the time of the transported clock.

  5. Sunrise equation - Wikipedia

    en.wikipedia.org/wiki/Sunrise_equation

    C is the Equation of the center value needed to calculate lambda ... latitude = 33.00801 longitude = 35.08794 elevation = 0 print (calc (time (), latitude, longitude ...

  6. Lunar distance (navigation) - Wikipedia

    en.wikipedia.org/wiki/Lunar_distance_(navigation)

    Knowing Greenwich time and local time, the navigator can work out longitude. [1] Local time can be determined from a sextant observation of the altitude of the Sun or a star. [8] [9] Then the longitude (relative to Greenwich) is readily calculated from the difference between local time and Greenwich Time, at 15 degrees per hour of difference.

  7. John Harrison - Wikipedia

    en.wikipedia.org/wiki/John_Harrison

    John Harrison (3 April [O.S. 24 March] 1693 – 24 March 1776) was an English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of how to calculate longitude while at sea.

  8. Geographic coordinate conversion - Wikipedia

    en.wikipedia.org/wiki/Geographic_coordinate...

    In geodesy, conversion among different geographic coordinate systems is made necessary by the different geographic coordinate systems in use across the world and over time. Coordinate conversion is composed of a number of different types of conversion: format change of geographic coordinates, conversion of coordinate systems, or transformation ...

  9. Marine chronometer - Wikipedia

    en.wikipedia.org/wiki/Marine_chronometer

    A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation.It is used to determine longitude by comparing Greenwich Mean Time (GMT), and the time at the current location found from observations of celestial bodies.