Radar description

Radar gets its name from a system of Radio Detection and Ranging.
How does radar work?
Radar transmits short pulses of radio waves that travel outwards, basically in straight lines.
When these waves hit a surface, like a vessel or a buoy, some of the waves are returned.
By measuring the time difference between transmission and reception of a reflected wave, the distance to an object can be calculated.
The direction in which the scanner is pointing when it receives the reflected wave represents the bearing of the object.