RADAR measures speed by which principle?Group of answer choicesSynthetic apertureDoppler effectRadar Cross Section (RCS)Range and bearing

RADAR measures speed by the principle of the Doppler effect. Here's a step-by-step explanation:

1. The RADAR system emits a radio wave at a specific frequency towards the object.
2. This radio wave hits the object and bounces back towards the RADAR system.
3. If the object is moving, the frequency of the returned wave will be different from the original wave. This is due to the Doppler effect.
4. The RADAR system measures this change in frequency.
5. Using the Doppler effect formula, the RADAR system can calculate the speed of the object. The formula is: Speed = (Change in frequency / Original frequency) * Speed of light.
6. Therefore, the speed of the object is determined by the Doppler effect.