ElliottDoppler

The first use of the Doppler Radar would be in a police radar gun. This is the true form of doppler radar, which is also commonly used by meteorologists on-air when predicting weather forcasts. However, that is a different, more specific type of doppler radar. The police gun radar has a transmitter and reciever in it. It shoots a wave of radiation at a moving object at a precise frequency. When it hits that object, which in this case would be a car, the wave bounces off the object at a different frequency and is sent back to the radar gun, which can then calculate the velocity of the object based off of the different frequency.

[] This shows the change in frequency when a police wave is reflected off of a speeding vehicle

The second use is known as Pulse-Doppler Radar. It is most commonly used by meteorologists when predicting weather patterns. It sends pulses of microwaves at different points to determine the change in both frequency and carrier cycles to determine radial velocity (or the circular motion in which the storm is moving). They use this to determine the speed, size, intensity, and type (snow, rain, hail) of storm that is coming based off of how the signals bounce back.

A thunderstorm line being viewed with pulse doppler radar.