Doppler Effect
A change in the frequency of a periodic wave due to the motion of the observer, the source, or both.
It occurs both in sound as well as electromagnetic phenomena, although it takes on different forms in each.
- Source toward stationary observer
- Source away from stationary observer
- Observer toward stationary source
- Observer away from stationary source
- where
- c = wave velocity in fluid [ms-1]
- f = emitted frequency [Hz]
- f' = observed frequency [Hz]
- Vs = velocity of source [ms-1]
- Vo = velocity of observer [ms-1]
- f = emitted frequency [Hz]
See also: Blue Shift, Doppler Sonar, Frequency, Redshift.
Subjects: Physics
- Further reading:
- Advanced Physics for You, , Nelson Thornes
- Weblinks:
- Acoustics and Vibrations Animations A collection of animations produced by Daniel A. Russell, Ph.D., Associate Professor of Applied Physics at Kettering University.


