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Convert Doppler shift to speed


radvel = dop2speed(Doppler_shift,wavelength)


radvel = dop2speed(Doppler_shift,wavelength) returns the radial velocity in meters per second. This value corresponds to the one-way Doppler shift, Doppler_shift, for the wavelength, wavelength, in meters.


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Calculate the radial velocity of an automobile based on the Doppler shift of a continuous-wave radar. The radar carrier frequency is 24.15 GHz. Assume a doppler shift of 2.880 kHz.

f0 = 24.15e9;
lambda = physconst('LightSpeed')/f0;
dopshift = 2.880e3;
radvel = dop2speed(dopshift,lambda)
radvel = 35.7516

The radial velocity is approximately 35.75 meters per second or 80 miles/hour.

More About

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Doppler-Radial Velocity Relation

The radial velocity of a source relative to a receiver can be computed from the one-way Doppler shift:


where Vs,r denotes the radial velocity of the source relative to the receiver, Δf is the Doppler shift in hertz, and λ is the carrier frequency wavelength in meters.


[1] Rappaport, T. Wireless Communications: Principles & Practices. Upper Saddle River, NJ: Prentice Hall, 1996.

[2] Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.

Extended Capabilities

Introduced in R2011a

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