The technique of position-finding by reference to celestial bodies. An observer uses a sextant to observe the altitude of a celestial body, such as the Sun, the Moon, a planet, or a bright star. From several observations of the same object at different times, or of different objects at the same time, the observer's position can be calculated. Traditional astronavigation on Earth has been largely superseded by methods using artificial satellites or radio beacons.
Subjects: Astronomy and Astrophysics.