Applications of the Doppler Effect

Doppler Effect has various applications some of which are discussed below:

• The Doppler effect helps in measuring the speed of oncoming vehicles.
• It is also often used in robotics for dynamic real-time path planning.
• It is used in astronomy to estimate the speed at which a star or a galaxy is approaching or receding from us.
• It is also used in radar to calculate the speed of detected objects.
• It is also used in satellite communication and satellite navigation.
• In the medical field, it is used to measure the velocity of the blood.

Doppler effect or Doppler shift phenomenon was described in 1842 by an Austrian physicist, Christian Doppler, and it is named after him. The Doppler effect or Doppler shift is a change (increase or decrease) in the frequency of a wave as the source and the observer move (towards or away from) each other relative to the medium. Based on the direction of the source and the observer and the magnitudes of their velocities, the observed frequency can be less or more than the source frequency. For example, the pitch of the sound of an ambulance siren changes as it passes us. It happens because of the relative velocity between the source and the observer. When the ambulance is approaching us, the relative velocity is negative, and the relative velocity is positive when it is moving away. So, that is the reason behind the difference in the pitch of the sound of the ambulance siren while it is approaching and while it is moving away. The Doppler effect applies to all types of waves, including sound and light. The Doppler effect is responsible for the Blue Shift or Red Shift phenomenon observed in light waves. The Doppler effect is used in various fields such as radar, astronomy, satellite communication and navigation, medical imaging, etc.