Radar is a revolutionary discovery of World War II.
Its initials are from the words Radio Direction and Ranging.
It consists of a rotating antenna and a screen and can provide distance and far-sightedness under all weather conditions.
The antenna emits a beam of very high frequency radio waves traveling at the speed of light (300,000 kilometers per second).
These radio waves are reflected on any object and return to the transceiver.
Then you measure the time between transmission and reception and so the distance is calculated. The point of the object is determined by the direction of the antenna when transmitting and receiving the signal.
[Source: http://www.ortsa.gr]
