shot noise

(redirected from Photon noise)
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Related to Photon noise: Shot noise

shot noise

See noise.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Shot Noise

 

random changes (fluctuations) in voltage and current relative to their mean value in the circuits of amplifiers, radios, and other electronic devices; caused by the shot effect in vacuum electronic and semiconductor instruments. For example, shot noise appears as acoustic noise in the loudspeaker of a radio, “snow” on a television screen, and “grass” on a radar screen. Shot noise is the basic component of the internal noises of electronic devices, which cause the distortion of weak signals and limit the sensitivity of amplifiers.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

shot noise

[′shät ‚nȯiz]
(electronics)
Noise voltage developed in a thermionic tube because of the random variations in the number and the velocity of electrons emitted by the heated cathode; the effect causes sputtering or popping sounds in radio receivers and snow effects in television pictures. Also known as Schottky noise; shot effect.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

shot noise

(Schottky noise) The random emission and velocity of electrons from a cathode, which was discovered by Walter Schottky. See Schottky.
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References in periodicals archive ?
To evaluate the potential improvement by FCN, we investigate the effects of photon noise on the material decomposition algorithms.
In the case of photon noise, the bias and SD of the competing algorithms have increased in varying degrees.
The second reason to use filters is to reduce photon noise, caused by the well-known multiplex disadvantage of the FTS [16], which, in some cases, counterbalances its clear multiplex advantage.
This distributed noiserecorded in the interferogram (photon noise from the entire bandpass contributes to the recorded signal at each mirror step) is transferred to the spectrum after the FFT.
This may be another reason optimal extraction is especially suitable for faint targets: with faint objects, photon noise dominates all other sources of error, but for bright objects, photon noise will be very small and other sources of error (e.g.
A dynamic range of 104 makes the sensor superior to standard X-ray films, and the signal-to-noise ratio is almost limited by the X-ray photon noise.
However, most point scanning systems require several seconds to capture images that are sufficiently free from photon noise.
Photon noise (shot noise) will increase at f/4, but not as much as the signal, so the SNR is still better.