# Doppler shift

Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

## 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.

## 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.

## 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
References in periodicals archive ?
This is because the influence of Doppler Effect is getting stronger with the increasing bandwidth which is the Delay Spread: Frequency Selective Fading and Doppler Shift. Based on the calculation, the higher the bandwidth, the stronger the Doppler Spread: Frequency Selective Fading and the Doppler Shift.
The relative Doppler shift A is defined as a ratio of source relative velocity to propagation wave velocity.
Learning from the figure, when the user terminal seeing the satellite rising from ground level, We can obtain the maximum positive Doppler shift. When the satellite ground station directly above, the Doppler shift is zero; when the satellite from the ground disappeared, the Doppler shift is the maximum negative Doppler shift.
Meanwhile, K and D denote the maximum resolvable division of Doppler shifts and channel delays, respectively.
where [f.sub.d] is the maximum Doppler shift due to mobile sources, [[phi].sub.p] is the phase shift due to the reflection coefficient of scatterers, and [[alpha].sub.p] is defined similarly as in (1).
Modulation order M 8 Fading sequence length (N) 180019 [[phi].sub.n], [[theta].sub.n] Uniformly distributed random variables [[phi].sub.n] = [[theta].sub.n] = 2 x pi x rand (1, N) - pi; Doppler shift 0,10,100 Hz SNR 0-35 dB TABLE 3: Sound signals used in generating the training set of the classifier.
to analyze the autocorrelation coefficient of the amplitude and field strength distribution [13-15], and some analytical formulas for Doppler shift and bandwidth of radar echoes backscattered from time-varying sea surface are derived by Wang et al.
The device measures a Doppler shift when movement beneath the probe is detected.
Doppler shift [f.sub.Dpp] and bandwidth [delta][f.sub.pq] are generally considered as the first- and the second-order moments of Doppler spectrum and weighted by scattering power [22, 26].
Higher frequencies are impacted more by Doppler shift than are lower frequencies; thus, signals can suffer significant spectral compression when platforms are traveling at velocities common to space missions.
In this case the correlation coefficient could be calculated as cross-correlation of the measured and prerecorded signal spectrums in the possible Doppler shift area
The frequency difference (Doppler shift amount) of these two light components is detected on the surface of a photo detector by a phenomenon called optical beating (when two waves mix, the resulting sum of waveforms has a 'beat frequency' that is equal to the difference between the two original wave frequencies).

Site: Follow: Share:
Open / Close