Doppler Radar

http://www.noaanews.noaa.gov/stories2004/s2311.htm

The Doppler Radar uses the Doppler effect to measure velocity at a distance using microwave signals for a specific location. It is commonly used to make atmospheric profiles of clouds, which it does by using the microwave signals. Doppler radar is able to keep track of the change in movement of clouds, and precipitation which makes it useful to track storms. The above shows the Doppler tracking a storm over a certain area.