Doppler Effect and Velocity Measurement
Doppler Effect : the apparent frequency of waves changes I there is a non-zero relative velocity between the wave source and the observer.
The Doppler frequency F, is the amount of frequency shift :
Doppler shift.
relative,velocity
speed of Light
angle of arrival
The accuracy of the Doppler measurement of velocity is a function of the relative angle between the antenna and target. If this angle becomes too large, then a serious error will emerge.
The motion of the target relative to the radar antenna will produce a Doppler shift of the original radar signal.
If a sample of the original signal Fo is mixed with the Doppler-shifted reflected signal Fd, then the difference signal F = Fo- F, is output to the fitter circuit.
This circuit limits the signal, bandwidth'to the expected Doppler-shifted F component.
A counter or discriminator circuit will yield the velocity data.
Doppler Effect and Velocity MeasurementDoppler Effect : the apparent frequency of waves changes I there is a non-zero relative velocity between the wave source and the observer.The Doppler frequency F, is the amount of frequency shift :Doppler shift.relative,velocityspeed of Lightangle of arrivalThe accuracy of the Doppler measurement of velocity is a function of the relative angle between the antenna and target. If this angle becomes too large, then a serious error will emerge.The motion of the target relative to the radar antenna will produce a Doppler shift of the original radar signal.If a sample of the original signal Fo is mixed with the Doppler-shifted reflected signal Fd, then the difference signal F = Fo- F, is output to the fitter circuit.This circuit limits the signal, bandwidth'to the expected Doppler-shifted F component.A counter or discriminator circuit will yield the velocity data.
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