What is - navigation?

What is - navigation?
Navigation — finding of a way, and usually this term is used in relation to sea vessels or to air transport. For hundreds of years seamen determined the width by the changing provision of the sun and stars. Knowing a difference between time by the ship and time exposed on zero longitude (0) across Greenwich they could define the location more precisely.

Today many navigation tools electronic and very exact. Radio beacons and satellites send signals by which the ship can determine the location. Then the navigator uses a compass to hold the vessel on the correct course.

With navigation sea vessels, planes and spaceships are helped by computers, defining their location is extremely exact.
For determination of coordinates (width and longitude) the ship such device as the sextant measuring a corner between a certain star or the sun and the horizon can be used. As soon as the corner is measured, the arrangement of this star exactly at present year can be checked according to very exact table. It allows to calculate location of the ship. Making a series of measurements by a sextant, the ship can stick to the correct course.

In modern navigation the satellite technology is applied to send from one place to another radio signals. Tools are very exact and allow sea vessels, planes and space aircraft to know the location ideally precisely.
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