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Convert Doppler shift to speed



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


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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 35.75 meters per second or 80 miles/hour.

Input Arguments

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One-way Doppler shift in hertz, specified as a scalar, vector, or matrix.

Data Types: single | double

Wavelength in meters, specified as a positive scalar.

Data Types: single | double

Output Arguments

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Radial velocity in meters per second, returned as a scalar, vector, or matrix.

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.

Extended Capabilities

Version History

Introduced in R2011a