Encyclopedia of Science | Radar

• Basic radar operation
• Radar and World War II
• Other uses of radar

Radar (a contraction of radio detection and ranging) is an electronic system that measures the position, speed, or other characteristics of a far-off object by means of radio waves bounced off the surface of that object. It can pierce any atmospheric disturbance, such as a storm, all the way to the horizon. Within its range, radar can reveal clouds, a landmass, or objects such as ships, airplanes, or spacecraft. Radar can measure distance to a target object; for instance, aircraft use it to determine altitude. Radar is also used to monitor atmospheric systems, to track storms, and to help predict the weather. Military applications include weapons ranging (determining the distance from a weapon to a target) and...