Doppler effect


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Related to Doppler effect: Doppler radar, CT scan, MRI

Doppler effect

 [dop´ler]
the relationship of the apparent frequency of waves, as of sound, light, and radio waves, to the relative motion of the source of the waves and the observer, the frequency increasing as the two approach each other and decreasing as they move apart.

The Doppler effect can be experienced when a train whistle or automobile horn produces a continuous sound as it approaches and passes a listener. The pitch of the sound suddenly falls as the source passes the listener.

Dopp·ler ef·fect

(dop'lĕr),
a change in frequency observed when the sound source and observer are in relative motion away from or toward each other.
See also: Doppler shift.
Synonym(s): Doppler phenomenon

Doppler effect

Etymology: Christian J. Doppler; L, effectus
the apparent change in frequency of sound or light waves emitted by a source as it moves away from or toward an observer. The frequency increases as the source moves toward the observer and decreases as it moves away, as the rising pitch of the whistle of an approaching train and the falling pitch of a departing train. The Doppler effect is also observed in electromagnetic radiation, such as light and radio waves. Also called Doppler shift. See also electromagnetic radiation, ultrasonography, wavelength.

Dopp·ler ef·fect

(dop'lĕr e-fekt')
A change in frequency observed when the sound and observer are in relative motion away from or toward each other.
See also: Doppler shift

Doppler effect

A change in the frequency of waves, such as sound or light, received by an observer, when the source is moving relative to the observer. The frequency increases when the source is approaching and decreases when it is retreating. The Doppler effect is used in a number of medical applications including measurement of blood flow and investigation of dynamic heart function. (Christian Johann Doppler, 1803–53, Austrian physicist).

Doppler effect

The principle that the sound of an object moving toward you has a higher pitch than the sound when it is moving away from you.

Doppler,

Christian J., Austrian mathematician and physicist in U.S., 1803-1853.
Doppler bidirectional test
Doppler echocardiography - use of Doppler ultrasonography techniques to augment two-dimensional echocardiography by allowing velocities to be registered within the echocardiographic image. Synonym(s): duplex echocardiography
Doppler effect - a change in frequency is observed when the sound and observer are in relative motion away from or toward each other. Synonym(s): Doppler phenomenon; Doppler principle
Doppler flow test
Doppler measurement
Doppler phenomenon - Synonym(s): Doppler effect
Doppler principle - Synonym(s): Doppler effect
Doppler probe
Doppler pulse evaluation
Doppler scope
Doppler shift - the magnitude of the frequency change in hertz when sound and observer are in relative motion away from or toward each other.
Doppler ultrasonography - application of the Doppler effect in ultrasound to detect movement of scatterers (usually red blood cells) by the analysis of the change in frequency of the returning echoes.
Doppler ultrasound flowmeter
Doppler ultrasound segmental blood pressure testing

Doppler

an Austrian physicist and mathematician.

duplex Doppler imaging
Doppler effect
the relationship of the apparent frequency of waves, as of sound, light and radio waves, to the relative motion of the source of the waves and the observer, the frequency increasing as the two approach each other and decreasing as they move apart.
The Doppler effect can be experienced when a train whistle or automobile horn produces a continuous sound as it approaches and passes a listener. The pitch of the sound suddenly falls as the source passes the listener.
Doppler shift
the change in frequency that occurs when high frequency sound waves are reflected from a moving surface; the basis for doppler ultrasound.
References in periodicals archive ?
The only work known to the present author is [12] where the emission theory and wave theory of Doppler effect are compared and shown to coincide within the first order in v/c but no conclusions about the actual applicability of the above corpuscular-based formula are made.
due to the Doppler effect, the dipole radiation temperature T (measured by the 1st derivative of the monopole) should be 0.
Thide says that weather radar could exploit the rotational Doppler effect to detect tornadoes before they reach the ground.
Now, thanks to the Doppler effect, a p/e pair can form all the e.
Oh dear," I said, shaking my head, which she probably missed, as this was a phone call, though she may have detected the Doppler effect created by the movement of the sound source, "for I must point out that 16pc of motorists say they've suffered road rage in the past year and 16pc have eaten in bed over the past month.
Using the Doppler effect of light, Slipher could determine that distant galaxies are moving away from us.
The Doppler Effect helped Aaslid to determine the velocity of the blood through these vessels.
Developed by Omani-based creative agency, Reality CG, the brand mark is an interpretation of the Doppler Effect, a physical phenomenon that illustrates Aaesound in motionAAE.
Used in air defense and air traffic control, a doppler radar employs the doppler effect of the returned echoes from targets to measure their radial velocity.
This shift in the frequencies creates an effect similar to the Doppler effect.
A very important property of the in-out waves is the Doppler effect between two space resonances(SR).

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