Q.What does RADAR stand for?

RADAR stands for RAdio Detection And Ranging -- one of the most important applications of communication systems, used to sense, detect and precisely locate distant objects such as aircraft, ships and spacecraft, and to determine the angle, range or velocity of objects entirely invisible to the human eye. A RADAR system's own antenna radiates an electromagnetic signal outward in all directions; when the signal strikes a target object it is reflected (or re-radiated) in many directions, and part of this reflected echo signal travels back to be picked up by the same radar antenna and delivered to the receiver for processing and amplification, from which the object's geographical statistics are determined. The target's range specifically is found from the time taken for the signal to make the full round trip from the radar to the object and back, at the known speed o …