The word RADAR is an abbreviation for Radio Detection And Ranging. Radar is an electromagnetic system for the detection and location of reflecting objects such as aircraft, ships, spacecraft, vehicles, people and the natural environment. In general, radar systems use modulated waveforms and directive antennas to transmit electromagnetic energy into a specific volume in space to search for targets. Objects (targets) within a search volume will reflect portions of this energy (radar returns or echoes) back to the radar. This small echo signal along with noise is processed by high sensitivity signal processor to determine the exact location, range, velocity, angular position, size and other target identifying information varying according to the type of radar used. Radar can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.