A computer combines the radar information with a map, so we can tell where rain is falling. Special software lets the system focus in on small areas, allowing forecasters to examine weather in towns and even neighborhoods.
The Doppler effect is a physical phenomenon named after Austrian physicist Christian Doppler. You may have experienced the Doppler effect if you've listened to the sound of a fast-moving object, such as a car or train, as it passes you. The pitch of the sound is higher as the object making the sound comes toward you. The pitch drops as the object passes you and moves away. The Doppler effect occurs because the sound waves are squeezed together as the object moves toward you, then stretched farther apart as the object moves away.
This effect doesn't just happen with sound waves. Light
and radio waves also show the Doppler effect. Doppler radar systems
use this principle to tell whether rain is moving closer or going
Doppler radar equipment and real-time data provided by