What is Doppler radar used for in...

The Doppler radar used in weather forecasting measures the direction and speed, or velocity, of objects such as drops of precipitation. This is called the Doppler Effect and is used to determine whether movement in the atmosphere is horizontally toward or away from the radar, which aides in weather forecasting. The radar was named for J. Christian Doppler, an Austrian physicist, who was the first to articulate the reason an approaching train’s whistle will sound higher than the whistle as the train moves away.