doppler effect/shift/principle/phenomenon

Introduction

The apparent change in the frequency of sound or electromagnetic radiation due to relative motion between the source & the observer.

Uses

• Of diagnostic value in cardiology & obstetrics
• used in radar:
  • to distinguish between stationary & moving targets
  • to provide information concerning their velocity, by measuring the frequency shift between the emitted & the reflected radiation

[from Johann Christian Doppler, Austrian mathematicican & physicist]

More general terms

• ultrasound (US, UTZ)

Additional terms

• doppler sonography/ultrasonography (DUS)