celestial navigation

noun
navigation by means of observations made of the apparent position of heavenly bodies.


Origin:
1935–40

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Collins
World English Dictionary
celestial navigation
 
n
Also called: astronavigation navigation by observation of the positions of the stars

Collins English Dictionary - Complete & Unabridged 10th Edition
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American Heritage
Science Dictionary
celestial navigation  
Navigation of a ship or aircraft based on the observed positions of celestial bodies. See more at altazimuth coordinate system.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Britannica
Encyclopedia

celestial navigation

use of the observed positions of celestial bodies to determine a navigator's position. At any moment some celestial body is at the zenith of any particular location on the Earth's surface. This location is called the ground position (GP). GP can thus be stated in terms of celestial coordinates, with the declination of the celestial object equal to latitude and the Greenwich hour angle equal to longitude. Almanacs such as those published by the Nautical Almanac Office of the U.S. Naval Observatory provide these coordinates for the Sun, Moon, and planets (or navigator's stars); the tabulations are given in terms of Greenwich Civil Time. From this information a line of position can be plotted. In principle, the line could be drawn on a very large sphere, but, in practice, a Mercator chart, or plotting sheet, is used. The navigator then uses a sextant or bubble octant to measure the altitude of the celestial object and records this altitude using Greenwich Civil Time. The navigator estimates his position, this being the dead-reckoning position. The altitude and the bearing that the celestial object would have at this position are calculated or taken from tables. The dead-reckoning position is marked on the plotting sheet and a line drawn in the direction of the celestial object's calculated bearing. From this information and from the difference between the observed and computed altitudes of the celestial object, known as the intercept, the position of the navigator can be calculated.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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Example sentences
Lewis himself had been trained by the country's leading scientists in botany,
  zoology, celestial navigation and medicine.
Another theory is that salmon use celestial navigation-the sun by day, stars by
  night-to guide them.
In addition, it is used for celestial navigation by using star-horizon or
  star-landmark measurements.
The students still learn both instrument and celestial navigation.
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