The Application Of the Doppler Effect

The Doppler effect is an essential concept for studying sound waves and frequencies. It is applicable in several scientific disciplines such as aeronautics, planetary science, and similar subjects. Christian Johann Doppler first introduced it in 1842. 

Before understanding the application of the Doppler Effect, let us first go through the fundamentals of the Doppler Effect. 

The Doppler Effect Basics 

Also known as the doppler shift, the doppler effect results from a change in the frequency of a wave from the perspective of an observer moving at a speed relative to the source of the wave. A common example of the Doppler effect is the shift in the pitch of a vehicle’s horn sound as it moves forward in the same direction. 

The Doppler effect takes place because each successive sound wave coming from the position gets closer to the observer. Therefore, it takes less time for each wave to move towards the observer than the previous wave. 

Applications of the Doppler Effect

Let us now look at the following points to understand the application of the Doppler effect in various fields – 

• Vibration measurement 

The doppler effect is also used in measuring vibration through the laser Doppler vibrometer. It is equipment that helps measure vibration by generating a laser beam moving towards the object’s surface. 

• Audio equipment

The Doppler Effect is used in some speakers that run on an electric motor to generate acoustics surrounding a loudspeaker. Due to this generation of acoustics, the sound generated from speakers moves in a circle resulting in fast-changing frequencies. 

• Radar 

The most common application of the doppler effect includes radars. A few radars use the doppler effect to determine the velocity of the target object. Investigation departments and police frequently used the radar to identify vehicles running at high speed and similar actions requiring the usage of a radar.

• Diagnosis and Treatment

The Doppler Effect also finds its application in the medical field in identifying vascular problems, including stenosis. The main reason for the application is the limitations of the echocardiogram, which is used to generate an accurate evaluation of the velocity of cardiac tissues and blood. It identifies the direction in blood flows at a given point in time. 

• Military 

The military uses the popular effect to identify a submarine’s speed and other equipment with the help of Sonars. The buoy is responsible for generating consistent and stable frequencies producing the Doppler Effect every time they come near an object in motion near the submarines. It also helps to record the velocity resulting from the object in motion every time it approaches the target object. 

• Aerospace Navigation 

Since radars are used in aerospace navigation, Doppler Effect helps calculate the speed of flying equipment, including drones, plane jets, and any other object frequently used for aerospace missions. Therefore, it can be said that The Doppler Effect is also applicable in aeronautical missions for the calculation of objects’ speed. 

• Astronomy 

Astronomy is another significant application of the doppler effect to calculate the speed at which stars rotate and if they are in a close range. This application is required because telescopes used for astronomical purposes have their limitations. They may not be able to serve the purpose when the given distance images are not appropriately clear. 

• Automobile Speed Measurement 

The doppler effect is also used to measure the speed of an automobile by calculating the change in radio waves which is observed through rotating satellites. An example includes a marine navigation system performing radar surveillance to calculate the speed of automobiles. 

The Doppler Effect and Sound Waves

This phenomenon explains the concept of the doppler effect in sound concerning the response of shockwaves. These are produced due to the movement of source waves and an upward shift in the frequency when the source and observer are receding. In this case, the Doppler effect is noticed when the speed of the primary source is relatively slower than the speed of the sound waves. However, if the primary source starts to move along at the same speed, the process is no longer the same as before. 

The Relativistic Doppler Effect

The relativistic effect explains the doppler effect with light concerning a fluctuation in the frequency of light due to the relative motion of the source and the observer. It is quite the opposite of the non-relativistic Doppler effect, and the equations usually include the time dilation effect of special relativity. It happens when the source moves towards the observer and perceived frequency goes above the levels of emitted frequency. 

Conclusion 

This article explains the application of the Doppler effect. Also known as the Doppler Shift, the Doppler Effect refers to the change in frequency of a moving wave concerning the relative motion of the observer and the wave source.. The Doppler Effect is applicable in flow measurement, vibration measurement, velocity profile measurement, radar, and many more use cases.