| 释义 |
Doppler shift
Thesaurus| Noun | 1. | Doppler shift - change in the apparent frequency of a wave as observer and source move toward or away from each otherDoppler effectpropagation - the movement of a wave through a medium |
Doppler shift
Doppler shift See Doppler effect.Doppler shift[′däp·lər ‚shift] (physics) The amount of the change in the observed frequency of a wave due to Doppler effect, usually expressed in hertz. Also known as Doppler frequency. Doppler shift Doppler effect in moving receiver.In airborne Doppler radar, a transmitter which, by means of a directional antenna, radiates energy toward the ground. This results in a situation in which both the transmitter and the receiver are moving relative to the ground; consequently the original frequency is changed twice. The difference between transmitted and received frequencies is known as the Doppler shift and is very nearly proportional to the relative motion between the aircraft and the ground along the direction of the radar beam. A moving target will cause the frequency of the echo signal to increase if it is approaching the radar or decrease if it is receding from the radar. Since the Doppler frequency shift is proportional to radial velocity, a radar system that measures such a shift in frequency can also provide the radial velocity of a target. The Doppler frequency shift also is used to separate moving targets from stationary ones even when the undesired clutter power might be much greater than the power of echo from the targets. Also called the Doppler effect.Doppler shift
Dopp·ler shift (dop'lĕr), the magnitude of the frequency change in hertz when sound and observer are in relative motion away from or toward each other.
See also: Doppler effect. Dopp·ler shift (dop'lĕr shift) The magnitude of the frequency change in hertz when sound and observer are in relative motion away from or toward each other.
See also: Doppler effectDoppler, Christian J., Austrian mathematician and physicist in U.S., 1803-1853. Doppler bidirectional testDoppler echocardiography - use of Doppler ultrasonography techniques to augment two-dimensional echocardiography by allowing velocities to be registered within the echocardiographic image. Synonym(s): duplex echocardiographyDoppler 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 principleDoppler flow testDoppler measurementDoppler phenomenon - Synonym(s): Doppler effectDoppler principle - Synonym(s): Doppler effectDoppler probeDoppler pulse evaluationDoppler scopeDoppler 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 flowmeterDoppler ultrasound segmental blood pressure testingDoppler shift
Synonyms for Doppler shiftnoun change in the apparent frequency of a wave as observer and source move toward or away from each otherSynonymsRelated Words |