How does Doppler radar tell the weather?
Radar stands for RAdio Detection And Ranging. Developed during World War II to detect enemy planes, radio waves detect the presence and distance of a target. A radio signal is sent out, and the operator listens for a returning signal. If the radio signal hits an object, most of the energy is scattered, but some will be reflected back to the receiver. By analyzing the changes in the reflected signal, the operator can determine where the object is and how far away it is. Doppler radar makes use of the Doppler effect to determine not only the location and distance of a target, but also its speed. We have all experienced the “Doppler effect” with trains. As a train passes you, you may notice the pitch in the whistle changing from high to low. As the train approaches, the sound waves in the whistle are compressed, making the pitch higher than if the train were just sitting in the station. And as the train moves away, the sound waves are stretched, lowering the whistle’s pitch. The faster th
