HIGH RADAR SYSTEMS

                                        THE NATURE OF RADAR         

                       

 Radar is an  electromagnetic system for the detection and location of  objects. It operates by transmitting a particular  type of waveform, a pulse-modulated sine wave for example, and detects the nature of the echo signal.radar can be designed to see through those conditions impervious to normal human vision,such as darkness,haze,fog,rain,and snow.In addition. radar has the advantage of being able to measure the distance or range to the object.This is probably its most important attribute.The receiving antenna collect the returned energy and delivers it to a receiver, where it is processed to detect the presence of the target and to extract its location and relative velocity.The distance to the target is determined by measuring the time taken for the radar signal to travel to the target and back.Radar is a contraction of the words radio detection and ranging.There seem to be no other competitive techniques which can measure range as well or as rapidly as can a radar.The most common radar waveform is a train of narrow,rectangular-shape pulses modulating a sine wave carrier.The distance,or range, to the target is determined by measuring the time Tr taken by the pulse to travel to the target and return.