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	Olympus FluoView Resource Center: Signal-to-Noise Considerations
		Since noise, because of its Poisson characteristics in the fluorescence microscope, is equivalent to the square root of the mean signal, the dynamic range is the signal divided by the square root of the signal, and is therefore equivalent to the square root of the signal.
		If shot noise were the only significant noise component in the detected signal in the confocal microscope, the signal-to-noise ratio would increase directly with increasing pinhole size, enabling the value to be enhanced up to the point at which the pinhole diameter becomes too large to achieve the desired confocal optical sectioning effect.
		The shot noise associated with intrinsic fluctuations in the arrival of photons from the signal is external to the detector itself and cannot be reduced.
	www.olympusfluoview.com /theory/signaltonoise.html (3928 words)

	Shot noise - Wikipedia, the free encyclopedia
		Shot noise in electronic devices consists of random fluctuations of the electric current in an electrical conductor, which are caused by the fact that the current is carried by discrete charges (electrons).
		In quantum optics, shot noise is caused by the fluctations of detected photons, again therefore a consequence of discretisation (of the energy in the electromagnetic field in this case).
		Shot noise is measurable not only in measurements at the few-photons level using photomultipliers, but also at stronger light intensities measured by photodiodes when using high temporal resolution oscilloscopes.
	en.wikipedia.org /wiki/Shot_noise (503 words)

	Noise, Dynamic Range and Bit Depth in Digital SLRs
		The term "shot noise" arises from an analogy of the discrete photons that make up a stream of light, to the tiny pellets that compose the stream of buckshot fired from a shotgun (in particular, "shot" does not mean "photographic image").
		The histogram of the noise is approximately gaussian.
		Noise of width 8 levels on the 0-255 scale was added to a uniform gray background; then the bit depth was truncated by squeezing the levels by a factor eight and then re-expanding by a factor eight.
	theory.uchicago.edu /~ejm/pix/20d/tests/noise/index.html (2739 words)

	A Brief History of Shot Noise
		Shot noise was also investigated by Schottky in his 1918 paper on spontaneous current fluctuations in electric conductors [14].
		In particular, he showed that as the intensity tends to infinity, the probability distribution of the shot noise tends to a normal distribution.
		Progress on the numerical computation of the density of shot noise was reported by Richter and Smits [13] in 1974.
	eceserv0.ece.wisc.edu /~gubner/fpphist.shtml (774 words)

	Hamamatsu Learning Center: CCD Noise Sources and Signal-to-Noise Ratio
		Noise, arising from a variety of sources, is inherent to all electronic image sensors, and careful control of noise components, both in the design and operation of the CCD system, is necessary to ensure that the signal level relative to noise is adequate to allow capture of accurate image information.
		In general, the term shot noise is applied to any noise component reflecting a similar statistical variation, or uncertainty, in measurements of the number of photons collected during a given time interval, and some references use that term in place of photon noise in discussions of CCD noise sources.
		The shot noise component is governed by Poisson statistics, similarly to photon shot noise, and is equivalent to the square root of the dark signal.
	learn.hamamatsu.com /articles/ccdsnr.html (5991 words)

	Noise Modeling in SiGe HBTs - HF noise, transistors, low-noise amplifiers, noise modeling
		There are two ways to connect the base current shot noise source: either directly between the emitter and the base as shown in the figure, or between the emitter and an internal base node connected to the base through the base resistance.
		Since the base current shot noise is due to both components of hole and electron injections, the shot noise due to base current is partially correlated to the collector current shot noise.
		The HICUM noise model was replaced with a simple one that groups all of the collector and base current components that contribute to shot noise into two single noise sources connected similar to the accurate connectivity of method B, then the new correlation model was added to this modified noise model.
	rfdesign.com /mag/radio_accurate_highfrequency_noise (2161 words)

	Electron Charge from Noise
		Students are introduced to the concept that noise is an intrinsic and fundamental characteristic of electronic components and circuits.
		The Johnson noise across a resistor is amplified and measured at both room temperature and liquid nitrogen temperature for a series of different resistances.
		For the shot noise measurements a series of different currents are passed through a vacuum diode and the shot noise across the diode is measured at each current.
	courses.washington.edu /phys431/noise.html (312 words)

	Noise, Dynamic Range and Bit Depth in Digital SLRs -- page 2
		Independent noise sources combine in quadrature -- that is, the square of the total noise is the sum of the squares of the individual contributions.
		It should be emphasized that these plots take into account only read noise and shot noise, ignoring pattern noise and pixel non-uniformity, thermal noise, etc; these are safely ignored for exposure times of less than a second and ISO's of 400 and higher (and all but the highest exposure zones at ISO 200 or less).
		Photon noise, being a property of the light itself, couldn't care less what ISO is set in the camera; only the read noise enters into the question of whether the data amplification is as well done in software post-capture as it is by hardware during image capture.
	theory.uchicago.edu /~ejm/pix/20d/tests/noise/noise-p2.html (3210 words)

	Graduate Physics Laboratory Handbook: Thermal Noise
		From measurements of the thermal noise as a function of resistance and the shot noise as a function of diode current, values of Boltzmann's constant and the electronic charge may be calculated.
		Thermal noise may also be measured a as a function of temperature, and a value of absolute zero obtained.
		The theoretical basis for 1/f noise (so-called because its magnitude increases inversely with the frequency, f) is still a matter of active resea rch.
	www.physics.umd.edu /studinfo/courses/gradlab/glhb/noise.html (665 words)

	TSCM 101 - Noise and Sensitivity Tutorial
		Shot noise is caused by current flow flowing though any type of load or resistance.
		Thermal noise (or thermal agitation effect) however is based on Boltzmann's constant, the temperature, and the bandwidth of the signal.
		Noise is our friend in that it presents an easily calculated or modeled level, slight variations of this "floor" indicate the presence of a potential eavesdropping device, or signal that requires further investigation.
	www.tscm.com /TSCM101noise.html (1768 words)

	noise
		Noise figure is used to describe the noise contribution of a device.
		The noise power is proportional to the bias current, and, unlike thermal and shot noise, flicker noise decreases with frequency.
		Noise is a serious problem, especially where low signal levels are experienced, there are a number of common sense approaches to minimize the effects of noise on a system.
	www.qsl.net /va3iul/Noise/noise.html (2068 words)

	Shot noise measurements in Josephson junction circuits (Site not responding. Last check: )
		We perform measurements of the influence of shot noise in Josephson tunnel junctions (Fig.1).
		A smaller junction in its normal state is used as the shot noise source, while the larger junction or a SQUID acts as a threshold detector.
		Escape is predominantly determined by excitation due to the wide-band shot noise.
	ltl.tkk.fi /PICO/SHOT.htm (306 words)

	Noise and receivers
		Shot noise is noise due to random fluctuations in current flowing in a circuit due to discrete current carriers and exists in all electronic amplifying devices.
		Shot noise is quite predictable in a thermionic diode in temperature limited emission, but it is not as well predicted in other types of active devices.
		Noise temperature is proportional to power, the total noise temperature of two or more noise sources combined is the sum of the noise temperature of all of the sources.
	www.vk1od.net /gt/noise/noise.htm (1168 words)

	Measuring Junction Noise
		Shot noise is generated whenever current flows through a semiconductor junction, either in forward or reverse breakdown modes.
		Shot Noise is a statistical effect of event "clumping" when the events have an expected rate but independent times.
		Shot noise does not occur in conductors, where electrons are correlated like water in a hose.
	www.ciphersbyritter.com /RADELECT/MEASNOIS/MEASNOIS.HTM (1484 words)

	Jitter, Noise, and Signal Integrity at High-Speed: A Tutorial--Part II \| Audio DesignLine
		Shot noise is produced by individual quantized carrier flow (current) in a potential barrier with a random generation time or spatial distribution.
		Shot noise is directly proportional to DC bias current, as well as the charge of the carrier.
		Assuming that the amplitude noise ΔA(t) is superimposed on the amplitude waveform of A
	www.audiodesignline.com /204805374?cid=RSSfeed_audiodesignline_adlRSS (938 words)

	[No title]
		It is frequency independent (white noise) well into the GHz region.ª³Hó¨Shot noise modeling¨7The noise amplitude is represented by the rms value: ª5ó ¨Shot noise modeling¨ÝThe rms noise current for a diode current of 1 mA is about 20 pA/Hz1/2.
		A parallel current source (in) can be added to a diode to account for the shot noise.¡ ÞC.çÿçÿçÿçÿ9ª>ó ¨Shot noise modeling¨Examples: For a diode current of 1 mA in a bandwidth of 1 MHz shot noise generates about 20 nA of noise current.
		It is often the dominating noise factor in the low-frequency region.
	www.csus.edu /indiv/n/ngw/EEE-243/Noise.ppt (635 words)

	Shot Noise - Qwiki
		Shot noise is a term describing the random fluctuations in a measurement signal due to the random arrival time of the signal carriers (electron, photon, etc.).
		The process for an electrical current is first described, then related to noise spectra and optical shot noise.
		A condensed matter scattering theory approach to photon shot noise.
	qwiki.caltech.edu /wiki/Shot_Noise (337 words)

	Session Q32 - Quantum Point Contacts & Shot Noise in Mesoscopic Systems.
		Shot noise is the time-dependent fluctuations in the electrical current caused by the discreteness of the electron charge.
		Noise spectra in adiabatically-shaped three-dimensional nanowires, modeled via hard- or soft-wall confining potentials, are studied in field-free conditions and under the influence of an applied magnetic field, as well as finite voltages.
		In a magnetic field the shot noise peaks split and shift due to lifting of degeneracies and shifting of the energies of the conduc ting modes.
	flux.aps.org /meetings/YR98/BAPSMAR98/abs/S3480.html (1977 words)

	Choosing CCD Equipment
		Read noise has a very important and distinctive characteristic: the uncertainty is the same (for example, plus or minus 10 electrons) no matter how long the exposure is. This means that the read noise is the same for a 1-second exposure and a 1-hour exposure.
		Research shows that the quantum noise in a signal is equal to the square root of the signal.
		This all leads to this idea: an exposure that is dominated by shot noise (let's say that this means that the read noise is 5% or less of the total noise) has noise characteristics that are almost completely determined by the total exposure time, not the individual exposure times.
	www.newastro.com /newastro/tutorials/noise/noise.asp (949 words)

	Electronic noise - Wikipedia, the free encyclopedia
		Thermal noise and shot noise are inherent to all devices.
		Johnson-Nyquist noise (sometimes thermal noise, Johnson noise or Nyquist noise) is the noise generated by the equilibrium fluctuations of the electric current inside an electrical conductor, which happens regardless of any applied voltage, due to the random thermal motion of the charge carriers (the electrons).
		Flicker noise, also known as 1/f noise, is a signal or process with a frequency spectrum such that the power spectral density is proportional to the reciprocal of the frequency.
	en.wikipedia.org /wiki/Electronic_noise (330 words)

	S/N, Part 4 - What to do about Noise
		Notice that shot noise is the only source of noise not under our control: it represents the minimum amount of noise that we could possibly get away with under the best of conditions, with the best camera.
		Shot noise is represented by the first term under the square root in the SNR equation, namely QE(P+B)t.
		Shot noise is inescapable, so we want to choose an exposure so as to make the other sources of noise relatively small.
	www.telescopes.cc /forums/index.php?topic=105.msg505 (1082 words)

	CalibrationByShotNoise
		The shot noise component depends on the the charge integrated between frame reads.
		It is this constant that we extract from measurements of noise.
		The shot noise added in quadrature with the electronics noise for the two reads equals the CDS standard deviation.
	www-rnc.lbl.gov /~wieman/CalibrationByShotNoise.htm (133 words)

	Molecular Expressions Microscopy Primer: Digital Image Processing - Reducing Noise
		The word “noise” is used to describe portions of an image (or any electronic signal) that do not represent the original scene, but instead arise in the detector or electronics, or in some other way (e.g., flickering fluorescent lights, printing technology, etc.).
		That is not always the case for noise reduction filters, depending on whether the noise is different in the various channels (which in turn depends on where it originates and on the camera design).
		Periodic noise, arising from vibration, electronic interference, halftone printing, fluorescent lighting, or other causes is difficult or impossible to remove with neighborhood operations in the spatial or pixel domain, because it extends throughout the image.
	micro.magnet.fsu.edu /primer/digitalimaging/russ/reducingnoise.html (1556 words)

	SHOT NOISE - Storming Media
		The objective of this research continues to be the study of shot noise models and their application to the development of computationally feasible procedures for image detection problems.
		These cases are shot noise in a parallel-plate diode, a series of pulses with random amplitudes and intervals, and for a series of pulses with random...
		The effect of signal and background shot noise, as well as device noise, on the performance of a direct-detection spatial tracking system is investigated for arbitrary detectors as a function of background radiation and detector radius is then analyzed and compared with some performance bounds.
	www.stormingmedia.us /keywords/shot_noise.html (4020 words)

	Noise in Audio Amplifiers
		Thermal noise is "white" in character (has a constant energy per unit bandwidth) and is generated by the thermal agitation of electrons in a conductor.
		This is the equivalent of 80dB Signal to Noise ratio (S/N) relative to 0dBu.
		A common technique for low noise is to select transistors based on their noise data, which will indicate the optimum collector current for a given source impedance.
	sound.westhost.com /noise.htm (2366 words)

	Origin of Shot noise in CdTe detectors
		The figure on the left summarizes in a single plot the measured current noise spectra.
		The dotted line at high frequencies indicates the intrinsic limit of the measuring instrument due to the voltage noise of the two input amplifiers that produce a correlated current signal through the detector capacitance of 1pF.
		This dumping of the shot noise produced by generation-recombination mechanisms, rarely seen before, could trigger interesting insights into the physics of these semiconductor materials.
	www.elet.polimi.it /upload/sampietr/spectrum/shotCdTe.html (371 words)

	Technology Demonstration: Criteria, System Characterization and Data Processing (Site not responding. Last check: )
		The shot noise (Table 1, line 2) is the square root of the measured signal (line 1).
		The fractional instrument noise (all noise sources except photon-shot noise and stellar variability) is converted to an absolute noise and given in line 3.
		Using the optimum PSF, the noise was measured as a function of the aperture size in pixels for each stellar magnitude and is given in Table 2.
	www.kepler.arc.nasa.gov /Tech_criteria.html (1753 words)

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