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It is not Doppler frequency. It's Doppler effect.

The APPARENT change in the frequency of the source as there is a relative motion between the source and the observer is defined as Doppler effect.

The expression for frequency (apparent) is given

fapparent = [(C - Vo + Vm)/(C-Vs+Vm)] x freal

The condition to be kept in mind is that the source is on the left side and the observer on the right side along positive X axis.

Vm - velocity of the medium and the medium is moving along positive X axis.

Vo - the velocity of the observer

Vs - the velocity of the source

C - velocity of the wave either sound or light

But in case of light Vm is not needed as the medium movement will not affect the velocity of the wave in any way.

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What does the Doppler radar measure?

A narrow microwave signal is directed at the moving vehicle at a known frequency, due to its motion the reflected signal will arrive back at the radar at a different frequency, an algorithm in the radar processor converts this difference to give the vehicles speed. Presumably the angle between the cop and the speeder will have to be taken into account as well.


What is the Doppler effect. How might the Doppler effect be used to measure velocity?

Doppler effect is a effect of a sound that comes from moving object. Sound travels at the speed of 343 meters per second in dry air at 20 degree Celsius. Suppose the object is coming you with high speed the sound waves will get compressed. If the object goes away from you with high speed the sound waves will get diluted. You must have noticed a vehicle with siren coming to you and going away from you. The pitch of the sound is different in both the cases. The computer can give you the real time calculation of the speed. speed can be calculated by the computer in very short duration of the span. May be second or two. This phenomena is widely used to locate the speed of the moving object. In the medical field, it is very valuable tool. The speed of blood flow can be transformed into different colors. Like in color Doppler ultrasound examinations.


What is difference between ultra sound and colour Doppler?

Ultra sound is just a name for soundwaves of a certain frequency. Doppler is a phenomena where wavelengths change depending on the movement of the object that the wave has bounced off from. By signal processing you can give different colours to objects that move differently wrt the sound source.


How does Longitudinal waves detect the position of an object?

The Doppler effect is used in radar to provide information regarding the speed of moving targets by measuring the frequency shift between the emitted and the reflected radiation. A transmitter produces pulsed radio frequency radiation. It is fed to a movable aerial from which it is transmitted as a beam. When the beam strikes the moving vehicle a part of the energy of the radiation is reflected back to the aerial. Signals received by the aerial are passed to the receiver, where they are amplified and detected. There will be a shift in frequency of the reflected wave and emitted wave due to the Doppler effect. The apparent frequency of the reflected wave is given by F = f ( 1 - v/c ) where v is the speed at which the source and the observer are moving apart and c is the speed of electromagnetic radiation, f is the real frequency or the frequency of the emitted signal The output of the detector is usually displayed on a cathode ray tube. The apparent frequency is measured and thus the speed of the vehicle is calculated. A heterodyne device may also be used in which beats are produced by superimposing the emitted radio wave over the reflected (from the vehicle) radio wave. In the heterodyne wave meter, a variable frequency local oscillator is adjusted to give predetermined beat frequency with the incoming reflected wave, enabling the frequency of the reflected wave which has had Doppler shift to be determined. Thus the speed of the vehicle can be determined.


How do you calculate the average frequency of a given dataset?

To calculate the average frequency of a given dataset, you would add up all the frequencies and divide by the total number of data points. This will give you the average frequency of the dataset.

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What does the Doppler radar measure?

A narrow microwave signal is directed at the moving vehicle at a known frequency, due to its motion the reflected signal will arrive back at the radar at a different frequency, an algorithm in the radar processor converts this difference to give the vehicles speed. Presumably the angle between the cop and the speeder will have to be taken into account as well.


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What is the Doppler effect. How might the Doppler effect be used to measure velocity?

Doppler effect is a effect of a sound that comes from moving object. Sound travels at the speed of 343 meters per second in dry air at 20 degree Celsius. Suppose the object is coming you with high speed the sound waves will get compressed. If the object goes away from you with high speed the sound waves will get diluted. You must have noticed a vehicle with siren coming to you and going away from you. The pitch of the sound is different in both the cases. The computer can give you the real time calculation of the speed. speed can be calculated by the computer in very short duration of the span. May be second or two. This phenomena is widely used to locate the speed of the moving object. In the medical field, it is very valuable tool. The speed of blood flow can be transformed into different colors. Like in color Doppler ultrasound examinations.


What is difference between ultra sound and colour Doppler?

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