Doppler shift

Doppler shift or Doppler effect is defined as the change in frequency of sound wave due to a reflector moving towards or away from an object, which in the case of ultrasound is the transducer.

Doppler equation 

F = 2fo(v/c)cos(Q)


  • F is Doppler frequency shift
  • fo is transmitted frequency from ultrasound probe
  • v is the velocity of moving reflector
  • c is the velocity of sound in the medium
  • Q is the angle between ultrasound beam and axis of flow

History and etmyology

Named after Austrian physicist, Christian Andreas Doppler (1803-1853) 1.

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Article information

rID: 25283
Section: Physics
Tag: refs, stub, cases
Synonyms or Alternate Spellings:
  • Doppler effect

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