Understanding Radar Radar is something that is in use all around us, although it is normally invisible. Airports use radar to track planes both on the ground and in the air, and also to guide planes in for smooth landings. Police use radar to detect the speed of passing motorists. NASA uses radar to map the earth and other planets, to track satellites and space debris and to help with things like docking and maneuvering. The military uses it to detect the enemy and to guide weapons.
Weathermen use radar to track storms, hurricanes and tornados.
Obviously radar is an extremely useful technology, and in this edition of How Stuff Works we will look at radar's secrets. In some cases radar can identify an object as well, for example identifying the type of an aircraft. They are trying to detect the speed of something - this is the reason why police use radar. They are trying to map something - the space shuttle and orbiting satellites use something called Synthetic Aperture Radar to create detailed topographic maps of the surface of planets and moons. These two concepts are easy to understand in the realm of sound because your ears hear echo and doppler shift every day.