The primary surveillance radars, are capable of detecting range and angle of aircrafts with high radar cross section. Small radar cross section causes instability. Detecting unwanted targets and also clutter effects in these radars cause reduction of performance. Most primary surveillance radars are not capable of providing additional information like height, type, or distinguishing friendly aircraft from enemy. Secondary Surveillance Radar overcome this issue by using transponders. Transponders provide the ability of sending a coded response to the earth station. This response can contain latitude, velocity, height, aircraft type, aircraft company and other information. This aircraft is easily traceable from the earth station.