The Doppler Effect is commonly used in RADAR systems for measuring what?

The Doppler Effect is a phenomenon that occurs when there is a relative motion between a source of waves and an observer. In the context of RADAR systems, it is primarily utilized to measure speed. When a radar signal is emitted towards a moving object, such as a vehicle, the frequency of the reflected signal changes depending on the object's velocity relative to the radar system. If the object is moving towards the radar, the frequency increases; if it is moving away, the frequency decreases. This change in frequency, known as the Doppler shift, allows the radar system to calculate the speed of the moving object accurately.

In performance analysis, using the Doppler Effect is particularly beneficial for applications like speed enforcement by law enforcement, where knowing the velocity of vehicles is crucial. Therefore, this makes it a key technique in RADAR systems for measuring speed rather than distance, direction, or altitude, which utilize different methods and principles.