Celestial navigation
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Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current phy
Ships Marine Chronometer giving an accuracy of less than ±5 seconds per year, French Navy issued, 1980
U.S. Navy quartermaster 3rd class, practices using a sextant as part of a navigation training aboard the amphibious assault ship USS Bonhomme Richard, 2018.
Two ship's officers "shoot" a morning sight with sextants, the Sun altitude (1963).
Sextant
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A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. Its primary use is to measure the angle between an astronomical object and the ho
Celestial navigation
…for the Sun and Moon at 12:00 GMT on October 29, 2005. At this time, a navigator on a ship at sea measured the Moon to be 56° above the horizon using a sextant. Ten minutes later, the Sun was observed to be 40° above the horizon. Lines of position were then calculated and plotted for each of these observations…
A sextant
Sextants can also be used by navigators to measure horizontal angles between objects.