about noise as an unwanted phenomenon Noise disambiguation File Noise Research Program on Hangar Apron ... engine noise in 1967 In common use, the word noise means any unwanted sound . In both analog electronics analog and digital electronics , Noise electronics noise is an unwanted perturbation to a wanted signal it is called noise as a generalisation of the audible noise heard when listening to a weak radio transmission. Signal noise is heard as acoustic noise if played through a loudspeaker it manifests as Noise video snow on a television or video image. Noise can block, distort, change or interfere ... of other activities. Signal to noise ratio is sometimes used informally to refer to the ratio ... theory , however, noise is still considered to be information . citation needed date April ... else can be considered noise. In biology, noise can describe the variability of a measurement around the mean, for example transcriptional noise describes the variability in gene activity between cells in a population. In many of these areas, the special case of thermal noise arises, which sets a fundamental ... are expressible by simple formulae. Subjective distinctions Calling some signal or sound noise is often ... s unbearable noise. Acoustic noise When speaking of noise in relation to sound, what is commonly meant ... . However, conversations of other people may be called noise for people not involved in any of them, and noise can be any unwanted sound such as the noise of dogs barking, neighbours playing loud ... noise can be anything from low level but annoying to loud and harmful. At one extreme users of public ... noise Main Noise regulation Noise regulation includes statutes or guidelines relating to sound ... a watershed passage of the U.S. Noise Control Act of 1972 1 , the program was abandoned at the federal ... not at all comprehensive or fully enforceable as to address a generally rising ambient noise b enforceable ... government. Acoustic noise in film sound For film sound theorists and practitioners at the advent ... more details
Mergeto Blame date August 2009 This article is about NOiSE the manga. For other uses, see Noise disambiguation . Infobox animanga Header name NOiSE image File Noisetstomunihei.jpg 230px caption Musubi on top of early silicon creatures ja kanji NOiSE genre Cyberpunk Infobox animanga Print type manga author Tsutomu Nihei publisher Kodansha publisher en flagicon United States Tokyopop publisher other flagicon France Gl nat publisher Gl nat br flagicon Germany Egmont Manga & Anime demographic Seinen manga Seinen magazine Afternoon magazine Afternoon first 2001 last 2001 volumes 1 volume list Infobox animanga Footer nihongo NOiSE Noizu is a one volume manga created by Tsutomu Nihei as a prequel to his ten volume work, Blame . Noise offers some information concerning the Megastructure s origins and initial size, as well as the origins of BLAME characters and structures Silicon Life .28Cyborgs.29 Silicon life . The book also includes Blame , a One shot comics one shot prototype for Blame , which originally debuted in 1995. Plot This story portrays Susono Musubi, a young police officer in a post apocalyptic subterranean city that s thriving with activity, who is investigating recent child abductions. She finds a heavily toned down, sword like Gravitational Beam Emitter as well as other elements that take different forms in the later publication for example, BLAME characters and structures Silicon Life .28Cyborgs.29 Silicon life . References reflist External links ann manga 5158 Blame DEFAULTSORT Noise Category Blame Category Cyberpunk anime and manga Category Manga of 2001 Category Seinen manga bg NOiSE de NOiSE fr NOiSE ja NOiSE ... more details
Infobox Album See Wikipedia WikiProject Albums Name This Is Noise Type EP Artist Rise Against Cover 61zGfvGp5yL. SS500 .jpg Released July 3, 2007 br April 7, 2008 small European release small January 15, 2008 UK digital release Recorded Genre Hardcore punk , punk rock Length 9 08 Label Geffen Records Geffen Producer Reviews Last album The Sufferer & the Witness br 2006 This album This Is Noise br 2007 Next album Appeal to Reason br 2008 This Is Noise is the first extended play EP by Rise Against . It was released on July 3, 2007 in Canada, and January 15, 2008 on iTunes by Geffen Records and features a song recorded at the same time as The Sufferer & the Witness album, a song recorded while they were on The Unraveling tour, and two songs from the Lords of Dogtown soundtrack. ref http www.riseagainst.com news default.aspx nid 12377 Rise Against NEWS This Is Noise EP Bot generated title ref A European track listing was announced on MySpace on March 31, 2008. It contains different artwork and different songs. The release dates were April 7, 2008 for Germany, the UK, Switzerland, and Italy, and April 11, 2008 for Austria. Track listing Boy s No Good small Lifetime band Lifetime cover small 1 18 Fix Me small Black Flag band Black Flag cover small 0 54 Obstructed View 2 02 But Tonight We Dance 2 47 Nervous Breakdown small Black Flag cover small 2 07 European track listing Obstructed View 2 03 But Tonight We Dance 2 48 Like the Angel Live at Warped Tour 2006 3 08 State of the Union Live at Warped Tour 2006 2 39 Everchanging Acoustic 4 21 Minor Threat small Live Minor Threat cover small 1 41 Nervous Breakdown small Black Flag band Black Flag cover small 2 07 References reflist Rise Against Category Rise Against albums Category 2007 EPs Category English language EPs es This Is Noise it This Is Noise ru This Is Noise sk This Is Noise ... more details
unreferenced date September 2008 POV date September 2008 lowercase Infobox Newspaper name The Noise image caption type Monthly newspaper format Tabloid foundation 1993 ceased publication price free owners Weavel Inc publisher Charles Seiverd editor Charles Seiverd language English circulation 45,000 headquarters POB 1637 br Flagstaff, Arizona Flagstaff , Arizona AZ 86002 br United States ISSN website http thenoise.us Official website the Noise is a monthly newspaper serving the cities of Flagstaff, Arizona Flagstaff , Prescott, Arizona Prescott , Sedona, Arizona Sedona , Cottonwood, Arizona Cottonwood , Jerome, Arizona Jerome , Clarkdale, Arizona Clarkdale , and Winslow, Arizona Winslow in northern Arizona . Founded in 1993 by four high school seniors whose rural hometown s budget cuts lead to the cancellation of the student newspaper, it has since expanded its circulation and editorial to encompass a large swath of northern Arizona. As an independent nonprofit publication, the Noise contains a variety of news , arts , music , poetry , fiction and commentary. It has housed in depth coverage of the controversial issue of snowmaking on the San Francisco Peaks by Arizona Snowbowl and the subsequent appeal from Native Americans in the United States Native American tribes to the Ninth Circuit Court of Appeals . It has also covered issues such as water rights, education reform, affordable housing, and immigration law. External links http www.thenoise.us Official website arizona newspaper stub DEFAULTSORT Noise Category Newspapers published in Arizona Category Flagstaff, Arizona ... more details
Infobox Film name Lodge Night image image size caption director Robert F. McGowan producer Hal Roach writer Hal Roach br H. M. Walker narrator starring Joe Cobb br Jackie Condon br Mickey Daniels br Allen Hoskins br Mary Kornman br Ernie Morrison br Jack Davis actor Jack Davis br Charles A. Bachman br Beth Darlington br Lewis DeVore br Helen Gilmore br Clara Guiol br Lincoln Stedman br Charles Stevenson actor Charles Stevenson br Charley Young music cinematography editing distributor Path Path Exchange released September 23, 1923 runtime 20 minutes country Film US language Silent film br English language English intertitles budget preceded by July Days film July Days followed by Stage Fright 1923 film Stage Fright No Noise is the 17th Our Gang short subject comedy released. The Our Gang series later known as The Little Rascals was created by Hal Roach in 1922 in film 1922 , and continued production until 1944 in film 1944 . Plot Mickey Daniels Mickey is in the hospital to have his tonsil s removed. The gang decide to visit him, and end up causing all sorts of disasters. They manage to work their way into both the x ray and operating rooms, among other places. Finally, the gang is subdued after inhaling some powerful nitrous oxide laughing gas . Notes The skeleton chasing the African American gag is repeated years later in the MGM Talkie era. When the television rights for the original silent Path Our Gang comedies were sold to National Telepix and other distributors, several episodes were retitled. This film was released into TV syndication as Mischief Makers in 1960 under the title Operation Tonsils . About two thirds of the original film was included. About two minutes of this film was edited with a film from the Hey Fellas a rival Our Gang series into another Mischief Makers episode under the title Rival Clinic . Cast Mickey Daniels Mickey Ernie Morrison Sunshine Sammy Allen Hoskins Farina Joe Cobb Joe Jackie Condon Jackie Mary Kornman Mary Jack Davis actor Ja ... more details
wiktionarypar noiseNoise is unwanted sound or signal. Noise may also refer different types of interference such as Noise audio , residual low level hiss or hum Noise video , snow on video or television pictures Image noise , related to digital photography Noise electronics , related to electronic circuitry Noise radio , interference related to radio signals Noise may also mean Industrial noise , hearing damage and industrial hygiene Noise figure , the ratio of the output noise power to attributable thermal noiseNoise spectral density , N sub o sub measured in Watt Hertz Noise economic , relates to a theory of pricing developed by Fischer Black Perlin noise , artificial pseudo random noise used for computer graphics effects Statistical noise , a colloquialism for recognized amounts of unexplained variation in a sample Noise probability , a collection of Sigma field sigma fields indexed by time intervals, representing information about a process with independent values In arts and culture Noise music , a noise based aesthetic in experimental music and sound art Power noise , a derivative of noise music NOiSE , a manga by Tsutomu Nihei Noise Goidelic mythology or Naoise, a figure in Irish mythology Noise Archive album Noise Archive album Noise DecembeRadio album Noise DecembeRadio album Noise 2007 Australian film Noise 2007 Australian film , a drama written and directed by Matthew Saville Noise 2007 U.S. film Noise 2007 U.S. film , a comedy drama written and directed by Henry Bean Noise programming block , a Fuji TV late night anime programming block Noise company , a second party video game developer for Nintendo Noise book Noise book , a 2006 popular science book by Bart Kosko disambig de Noise fr Noise homonymie it Rumore nl Noise ja NOISE no St y pl Szum ... more details
Youth Noise may refer to Youth Noise website , a youth based website Youth Noise organization , an organization based in Jordan disambig ... more details
Gradient noise is a type of noise commonly used as a procedural texture primitive in computer graphics. It is conceptually different, and often confused with value noise . This method consists of a creation of a lattice of random gradients , which are then interpolated to obtain values in between the lattices. An artifact of some implementations of this noise is that the returned value at the lattice points is 0. Unlike the value noise, gradient noise has more energy in the high frequencies. The first implementation of a gradient noise function is credited to Ken Perlin , who published the description of it in 1985. This noise is now commonly known as the Perlin noise . ref David Ebert, Kent Musgrave, Darwyn Peachey, Ken Perlin, and Worley. Texturing and Modeling A Procedural Approach. Academic Press, October 1994. ISBN 0 12 228760 6 ref See also Value noise Perlin noise Simplex noise Wavelet noise Worley noise References reflist Category Noise Category Computer graphic techniques graphics software stub ru ... more details
Joyful Noise can refer to Joyful Noise film Joyful Noise film , a music driven film by Todd Graff, starring Queen Latifah and Dolly Parton 2012 A Joyful Noise , a musical with a book by Edward Padula and music and lyrics by Oscar Brand and Paul Nassau 1966 Joyful Noise album Joyful Noise album , an album by The Derek Trucks Band 2002 A Joyful Noise Jo Dee Messina album A Joyful Noise Jo Dee Messina album , a Christmas album released by Jo Dee Messina 2002 Joyful Noise Poems for Two Voices , a children s book by Paul Fleischman 1989 Joyful Noise Recordings , a record label disambig ... more details
Unreferenced date July 2009 Gaussian noise is statistical noise that has its probability density function equal to that of the normal distribution , which is also known as the Gaussian distribution. In other words, the values that the noise can take on are Gaussian distributed. A special case is white Gaussian noise , in which the values at any pairs of times are statistically independent and uncorrelated . In applications, Gaussian noise is most commonly used as additive white noise to yield additive white Gaussian noise . Explanation Gaussian noise is properly defined as the noise with a Gaussian amplitude distribution. This says nothing of the correlation of the noise in time or of the spectral density of the noise. Labeling Gaussian noise as white describes the correlation of the noise. It is necessary to use the term white Gaussian noise to be precise. Gaussian noise is sometimes misunderstood to be white Gaussian noise, but this is not the case. See also Gaussian process References Reflist physics stub probability stub DEFAULTSORT Gaussian Noise Category Noise Category Stochastic processes Category Time series analysis es Ruido gaussiano it Rumore gaussiano su Gaussian noise zh ... more details
A noise print is part of a technique used in noise reduction . A noise print is commonly used in audio mastering to reduce the effects of unwanted noise from a piece of audio. In this case, the noise print would be a recording of the ambient noise in the room, which is then used to set multiple expanders, effectively gating out those frequencies whilst the signal level in that band is lower than that in the noise print. Many plugins for Studio software can be used to apply noise reduction in this way. Noise reduction usually results in unwanted Compression artifact artifacts , sometimes referred to as twittering or birdies . Different algorithms for noise reduction control these artifacts with varying levels of success. See also Dark frame analogous technique in image noise reduction Unreferenced stub auto yes date December 2009 DEFAULTSORT Noise Print Category Audio engineering Category Noise Electronics stub ... more details
Signal to Noise may refer to Signal to Noise comics , a 1992 graphic novel written by Neil Gaiman and illustrated by Dave McKean Signal to Noise novel , a 1998 cyberpunk novel by Eric S. Nylund Signal to Noise The Rise album Signal to Noise White Willow album Signal to noise ratio , a measure used in science and engineering to quantify how much a signal has been corrupted by noise dab ... more details
Wavelet noise is an alternative to Perlin noise which reduces the problems of aliasing and detail loss that are encountered when Perlin noise is Harmonic sum summed into a fractal . External links http graphics.pixar.com library WaveletNoise paper.pdf Wavelet Noise Paper at pixar.com. Category Computer graphics compu graphics stub ... more details
Value noise is a type of noise commonly used as a procedural texture primitive in computer graphics. It is conceptually different, and often confused with gradient noise examples of which are the Perlin noise and Simplex noise . This method consists of a creation of a lattice of points which are assigned random values. The noise function then returns the interpolated number based on the value of the neighboring lattice points. To improve the quality of the generated noise, multiple Octave electronics octaves of this noise can be generated and then summed together. This technique produces results very similar to Perlin noise at the cost of lower quality while having a simpler algorithm. ref David Ebert, Kent Musgrave, Darwyn Peachey, Ken Perlin, and Worley. Texturing and Modeling A Procedural Approach. Academic Press , October 1994. ISBN 0 12 228760 6 ref See also Gradient noise Perlin noise Simplex noise Wavelet noise External links http freespace.virgin.net hugo.elias models m perlin.htm An explanation and implementation of Value Noise mislabeled as Perlin noise , freespace.virgin.net References reflist Category Noise Category Computer graphic techniques graphics software stub ... more details
Unreferenced stub auto yes date December 2009 Colors of noise Image Gray noise spectrum.png thumb Gray noise spectrum Grey noise is random noise subjected to a psychoacoustic equal loudness curve such as an inverted A weighting curve over a given range of frequencies, giving the listener the perception that it is equally loud at all frequencies. This is in contrast to white noise , noise which is in fact equally loud at all frequencies but not perceived as such due to psychoacoustics . See Colors of noise . Listen filename Gray noise.ogg title 10 seconds of grey noise description Noise DEFAULTSORT Grey Noise Telecomm stub ca Soroll gris eo Griza bruo ru uk ... more details
Noise Records is a Germany German record label founded by German music industry personality Karl Ulrich Walterbach in 1984 in music 1984 as an expansion of the concept of his label Aggressive Rock Produktionen . Noise Records specialized in thrash metal . It is part of Sanctuary Records . See also List of record labels External links Official http www.noiserecords.com labels noise.shtml Category German record labels Category Record labels established in 1984 Category Heavy metal record labels Germany record label stub de Noise Records es Noise Records fa fr Noise Records hr Noise Records it Noise Records ja no Noise Records fi Noise Records sv Noise Records ... more details
A Noise generator is a piece of equipment used to produce random electrical noise, in order to test how electrical equipment may react to noise, or to measure the intensity of noise. Tube noise generators were used for true random number generation in tube era electronics . Examples include a triode thyratron tube in a magnetic field . ref cite web title World Power Systems, PDF, Sylvania Type 6D4 url http www.wps.com J million Sylvania Tube Data 1957 6d4 noise generator.pdf accessdate 6 November 2010 ref See also Avalanche diode Noise electronics Noise figure Noise figure meter Radio noise source References Reflist Category Electronic test equipment Technology stub ... more details
Noise in audio, recording, and broadcast systems refers to the residual low level sound usually hiss and hum that is heard in quiet periods of a programme. In audio engineering it can refer either to the acoustic noise from loudspeakers, or to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as hiss . This signal noise is commonly measured using A weighting or ITU R 468 noise weighting ITU R 468 weighting Noise is often generated deliberately and used as a test signal . Two types of deliberately generated noise in common use are referred to as white noise , which has a uniform spectral power density at all frequencies, or pink noise which has a power spectral density that falls at 3dB octave with rising frequency. The latter is often more useful in audio testing because it contains constant energy per octave and hence per commonly used 1 3rd octave , rather than a prepondance of energy at high frequencies. In other words it contains energy that is distributed geometrically rather than linearly. See also NoiseNoise music Noise music Noise measurement quiescent Noise electronics signal to quantization noise ratio ITU R 468 noise weighting A weighting Weighting filter Equal loudness contour External links http www.sengpielaudio.com calculator noise.htm White noise calculator, thermal noise Voltage in microvolts, conversion to noise level in dBu and dBV and vice versa Noise Category Noise Audio Category Audio electronics ... more details
Noise measurement is carried out in various fields. In acoustics , it can be for the purpose of measuring environmental noise , or part of a test procedure using white noise , or some other specialised form of test signal . In electronics it relates to the sensitivity of communications systems, the purity of signals, or the quality of audio systems . The concept is to define the noise level below which signals cannot reliably be detected. It can be thought of as uncertainty of the information being carried over a communications channel . In audio systems and broadcasting specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the differing spectral distribution and temporal properties of the noise that they generate. In particular, the ITU R 468 noise weighting was devised specifically for this purpose, and is widely used for professional audio and broadcast measurements. Standards There are a number of standards for noise measurement, each with a different goal or focus, including Standard ITU R BS 468 widely used in Broadcasting and professional Audio. Standard IEC A weighting is widely used in Environmental Noise measurement. Standard CCIR recommendation 468 4 is now maintained as ITU R BS 468 Standard CCITT 0.41 refers to Psophometric weighting used on telephone circuits. Standard CCITT P53 is now continued as CCITT0.41 Standard BS 6402 1983 specifies Personal sound exposure meters. Standard BS 3539 1968 specifies Sound level meter s for motor vehicle noise. Standard BSEN 60651 supersedes BS 5969 1981 Sound level meter s See also Audio quality measurement Rumble measurement NoiseNoise dosimeter Noise environmental Noise economic Noise music Noise pollution Signal noise ITU R 468 noise ... list of noise topics . External links http noboomers.home.insightbb.com default.htm Noboomers Noise Category Noise Category Noise pollution Noise measurement ... more details
Simplex noise is a method for constructing an n dimensional noise function comparable to Perlin noise classic noise but with a lower computational overhead, especially in larger dimensions. Ken Perlin designed the algorithm in 2001 ref Ken Perlin, Noise hardware. In Real Time Shading SIGGRAPH Course Notes 2001 , Olano M., Ed. . http www.csee.umbc.edu olano s2002c36 ch02.pdf pdf ref to address the limitations of his classic noise function, especially in higher dimensions. The advantages of simplex noise over Perlin noise Simplex noise has a lower computational complexity and requires fewer multiplications. Simplex noise scales to higher dimensions 4D, 5D and up with much less computational cost, the complexity is math O n 2 math for math n math dimensions instead of the math O 2 n math of classic Noise ref Ken Perlin, Making noise. Based on a talk presented at GDCHardcore Dec 9, 1999 . http www.noisemachine.com talk1 32.html url ref . Simplex noise has no noticeable directional artifacts is isotropic . Simplex noise has a well defined and continuous gradient everywhere that can be computed quite cheaply. Simplex noise is easy to implement in hardware. Whereas classical noise interpolates between the values from the surrounding hypergrid end points ie North South East West in 2D , Simplex noise divides the space into simplex es i.e. N dimensional equilateral triangles to interpolate between. This reduces the number of data points. While a hypercube in math N math dimensions has math 2 N math corners, a simplex in math N math dimensions has only math N 1 math corners. See also Perlin noise References references External links http staffwww.itn.liu.se stegu simplexnoise simplexnoise.pdf ... homepage2006 simplex noise index.html Perlin s animated rubber sheet simplex noise demo http staffwww.itn.liu.se stegu aqsis aqsis newnoise Another implementation of Simplex Noise in C SimplexNoise1234 Category Noise Category Computer graphic techniques ... more details
about physics term the Bright Eyes band Bright Eyes album Noise Floor Rarities 1998 2005 Unreferenced date June 2009 In signal theory , the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system. In radio communication and electronics, this may include thermal noise , blackbody , and any other interfering signals. In a measurement system such as a seismograph , it may include nearby foot traffic or a nearby road. The noise floor limits the smallest measurement that can be taken with certainty since any measured amplitude can on average be no less than the noise floor. A common way to lower the noise floor in electronics systems is to cool the system to reduce thermal noise, which is usually the major noise source. In special circumstances, the noise floor can also be artificially lowered with digital signal processing techniques. Signals can be detected that are below the noise floor by using different techniques of spread spectrum communications. Image Spectrum analyzer, display, noise floor.jpg Noise Category Noise Physics stub de Grundrauschen ... more details
In acoustics and specifically in acoustical engineering , background noise or ambient noise is any sound other than the sound being monitored. Background noise is a form of noise pollution or Interference communication interference . Background noise is an important concept in setting noise regulation s. See noise criteria for cinema home cinema applications. Examples of background noises are Noise environmental environmental noises such as waves , traffic noise, alarms , people talking, bioacoustics bioacoustic noise from animals or birds and mechanical noise from devices such as refrigerator s or air conditioning , power supplies or electric motor motors . The prevention or reduction of background noise is important in the field of active noise control . It is an important consideration with the use of ultrasound e.g. for medical diagnosis or imaging , sonar and sound reproduction . In astronomy , background noise or cosmic background radiation is electromagnetic radiation from the sky with no discernible source. In information architecture , irrelevant, duplicate or incorrect information may be called background noise. In physics and telecommunication , background signal noise can be detrimental or in some cases beneficial. The study of avoiding, reducing or using signal noise is information theory . In telephony , artificial comfort noise is used as a substitute for natural background noise, to fill in artificial silence created by discontinuous transmission systems using voice activity detection . See also Ambient noise level 4 33 External links http www.acoustics.salford.ac.uk acoustics info concert hall acoustics ?content unwanted sound How low noise levels are achieved in concert halls Category Acoustics Physics stub de Atmo ... more details
Acoustic noise is any sound in the acoustic domain, either deliberate music, speech, etc. or unintended. It is important to recognise that the term noise is also used to refer to other, non audible forms, especially in electronics and in the radio radar spectrum. Environmental noise main Noise pollution Environmental noise is the comprehensive study of acoustic phenomena in the human environment which involve unwanted sound. The principal sources of environmental noise are surface motor vehicles, aircraft, trains and industrial sources. These noise sources expose millions of people to noise pollution that creates not only annoyance, but also significant health consequences such as elevated incidence of hearing loss and cardiovascular disease. There are a variety of mitigation strategies and controls available to reduce sound levels including source intensity reduction, land use planning strategies, noise barrier s and sound baffle s, time of day use regimens, vehicle operational controls and architectural acoustics design measures.ankit k Laws governing noise main Noise regulation Environmental noise is governed by laws and standards which set maximum recommended levels of noise for specific land uses, such as residential areas, areas of outstanding natural beauty, or schools. These standards usually specify measurement using a weighting filter , most often A weighting . See also Impulse noise audio Loud music Noise Pollution External links http www.defra.gov.uk environment noise research climate nannexb.htm European noise laws http www.daniel alberts.info Papers AddressingWindTurbineNoise.pdf Addressing Wind Turbine Noise http www.nonoise.org Noise Pollution Clearing House Category Noise pollution Noise acoustic de Ger usch ... more details
Noise figure NF is a measure of degradation of the signal to noise ratio SNR , caused by components in a radio frequency RF Signal chain signal processing chain signal chain . The noise figure is defined as the ratio of the output noise power of a device to the portion thereof attributable to thermal noise in the input termination at standard noise temperature math T 0 math usually 290 Kelvin K . The noise figure is thus the ratio of actual output noise to that which would remain if the device itself did not introduce noise. It is a number by which the performance of a radio receiver can be specified. General The noise figure is the difference in decibel s dB between the noise output of the actual receiver to the noise output of an ideal receiver with the same overall gain and Bandwidth signal processing bandwidth when the receivers are connected to sources at the standard noise temperature math T 0 math usually 290 K . The noise power from a simple Electrical load load is equal ... the noise figure a useful figure of merit for terrestrial systems where the antenna effective temperature is usually near the standard 290 K. In this case, one receiver with a noise figure say 2 dB better than another, will have an output signal to noise ratio that is about 2 dB better ... a 2 dB improvement in receiver noise figure will result in more than a 2 dB improvement in the output signal to noise ratio. For this reason, the related figure of effective noise temperature is therefore often used instead of the noise figure for characterizing satellite communication receivers and low noise amplifier s. In heterodyne systems, output noise power includes spurious contributions from image frequency transformation, but the portion attributable to thermal noise in the input termination at standard noise temperature includes only that which appears in the output ... frequency transformation. Definition The noise factor of a system is defined as math F frac mathrm ... more details
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