Q.Give a classification of RADAR systems.

RADAR stands for Radio Detection And Ranging. It is a system that detects a distant object — called the target — and finds its exact location, range and even its velocity, by transmitting radio waves and listening for the waves reflected back. Radars work day and night and in all weather, give broad coverage, and are a principal navigational aid for ships, aircraft and missiles, as well as a key tool in defence.

The principle is simple: a scanning antenna radiates a powerful electromagnetic pulse; when the pulse strikes a target it is reflected, and a highly sensitive receiver picks up the returned wave, called the echo. The presence of an echo reveals the target, and the direction in which the antenna is pointing when the echo arrives gives the target's direction. …