The Doppler effect in radar works by analyzing the frequency shift of radio waves reflected from moving objects. When a radar system transmits radio waves toward a target, such as an airplane or vehicle, the waves are reflected back to the radar receiver after hitting the target. If the target moves toward or away from the radar, the frequency of the reflected waves changes due to the Doppler effect. Specifically, if the target moves toward the radar, the frequency increases (higher pitch), and if it moves away, the frequency decreases (lower pitch). This frequency shift is proportional to the speed of the target relative to the radar. By measuring this offset, radar systems can determine the speed and direction of the moving object.
The Doppler effect is essential in radar for measuring the speed of moving objects. In radar applications, such as air traffic control or speed enforcement, continuous wave (CW) radar systems use the Doppler effect to detect the speed of targets. The CW radar emits a continuous wave of radio frequency and compares the frequency of the transmitted and received signals. The frequency difference between transmitted and received signals, caused by the Doppler effect, provides information about the speed of the target. This technique is commonly used in police radar guns to accurately measure vehicle speeds on roads.
A radar gun uses the Doppler effect to measure the speed of moving vehicles. When a radar gun emits a radio wave toward a vehicle, the wave reflects off the vehicle and returns to the radar gun. The frequency of the returned wave is compared to the frequency of the emitted wave. If the vehicle moves towards the radar gun, the frequency of the returned wave is higher than the emitted wave due to the Doppler effect. Conversely, if the vehicle moves away, the frequency is lower. By measuring this frequency shift, the radar gun calculates the speed of the vehicle relative to the radar gun. Radar guns are commonly used by law enforcement for speed enforcement and traffic enforcement purposes due to their ability to accurately measure vehicle speeds in real time.