|
Sparklies
Sparklies is a form of interference on analogue satellite television transmissions. Sparklies are black or white 'hard' interference dots (as opposed to the 'soft' interference patterns of terrestrial television), caused either by too weak or too strong a signal. When within the satellite's rated reception footprint, sparklies are most likely to be caused by a misaligned dish, or LNBs which are too high- or too low- gain for the dish and receiver. The term "sparklies" is used by British Sky Broadcasting (BSkyB) and a number of hardware makers including Amstrad and Pace. Sparklies do not occur on digital satellite systems; similar problems with digital signals cause MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by International Organization for Standardization, ISO and International Electrotechnical Commission, IEC that sets standards for media coding, includ ... artifacts. See also * Salt and pepper noise References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Television
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes Noise (video), snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below digital cliff, a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the lower bandwidth requ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Television
Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.39, definition: ''Broadcasting-satellite service'' The signals are received via an outdoor parabolic antenna commonly referred to as a satellite dish and a low-noise block downconverter. A satellite receiver decodes the desired television program for viewing on a television set. Receivers can be external set-top boxes, or a built-in television tuner. Satellite television provides a wide range of channels and services. It is usually the only television available in many remote geographic areas without terrestrial television or cable television service. Different receivers are required for the two types. Some transmissions and channels are unencrypted and therefore free-to-air, while many other channels are transmitted with enc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Television
Terrestrial television, or over-the-air television (OTA) is a type of television broadcasting in which the content is signal transmission, transmitted via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an television antenna, antenna. The term ''terrestrial'' is more common in Europe and Latin America, while in Canada and the United States it is called ''over-the-air'' or simply ''broadcast''. This type of Television broadcasting, TV broadcast is distinguished from newer technologies, such as satellite television (direct broadcast satellite or DBS television), in which the signal is transmitted to the receiver from an overhead satellite; cable television, in which the signal is carried to the receiver through a coaxial cable, cable; and Internet Protocol television, in which the signal is received over an Internet stream or on a network utilizing the Internet Protocol. Terrestrial television stations broadcast on television cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Footprint (satellite)
The footprint of a communications satellite is the ground area that its transponders offer coverage (telecommunication), coverage, and determines the satellite dish diameter required to receive each transponder's signal. There is usually a different map for each transponder (or group of transponders), as each may be aimed to cover different areas. coverage map, Footprint maps usually show either the estimated minimum satellite dish diameter required or the signal strength in each area measured in dBW. See also *Satellite ground track References {{Reflist External links Links to fleet information and footprintsfrom SES. from Intelsat for their fleet of satellites. Links to interactive mapsfor SES World Skies's fleet of satellites. Link to mapsfor Russian Satellite Communications Company satellites Link to satellite footprintsfrom SatBeams for Geostationary satellites Satellite footprints as images and on Google Earth Satellites Satellite broadcasting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-noise Block Converter
A low-noise block downconverter (LNB) is the receiving device mounted on satellite dishes used for satellite TV reception, which collects the radio waves from the dish and converts them to a signal which is sent through a Coaxial cable, cable to the receiver inside the building. Also called a low-noise block, low-noise converter (LNC), or even low-noise downconverter (LND),Bains, Geoff. "Getting The Most Out Of An LNB" ''What Satellite & Digital TV'' (November, 2008) pp50-51 the device is sometimes inaccurately called a ''low-noise amplifier'' (''LNA''). The LNB is a combination of low-noise amplifier, frequency mixer, local oscillator and intermediate frequency (IF) amplifier. It serves as the RF front end of the satellite receiver, receiving the microwave transmission, microwave signal from the satellite collected by the dish, amplifying it, and Downconverter, downconverting the block of frequencies to a lower block of intermediate frequency, intermediate frequencies (IF). Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gain (electronics)
In electronics, gain is a measure of the ability of a two-port circuit (often an amplifier) to increase the power or amplitude of a signal from the input to the output port by adding energy converted from some power supply to the signal. It is usually defined as the mean ratio of the signal amplitude or power at the output port to the amplitude or power at the input port. It is often expressed using the logarithmic decibel (dB) units ("dB gain"). A gain greater than one (greater than zero dB), that is, amplification, is the defining property of an active device or circuit, while a passive circuit will have a gain of less than one. The term ''gain'' alone is ambiguous, and can refer to the ratio of output to input voltage (''voltage gain''), current (''current gain'') or electric power (''power gain''). In the field of audio and general purpose amplifiers, especially operational amplifiers, the term usually refers to voltage gain, but in radio frequency amplifiers it usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Sky Broadcasting
Sky UK Limited (formerly British Sky Broadcasting Limited (BSkyB)), trading as Sky, is a British broadcaster and telecommunications company that provides television, broadband internet, fixed line and mobile telephone services to consumers and businesses in the United Kingdom. It is a subsidiary of Sky Group (currently owned by Comcast) and is headquartered at the Sky Studios in Isleworth. Sky is a major media company and the largest British broadcaster by revenue. It operates the Sky News news media organisation, Sky Sports which is the largest sports TV broadcaster in the UK, and the Sky Studios film and TV production company. Sky is also the country's leading provider of pay-TV services (12.7 million customers as of the end of 2019) through its satellite TV platform Sky Q as well as the IPTV-based Sky Glass and Sky Stream products. Its flagship channels include Sky Showcase, Sky Max, Sky Witness, Sky Documentaries, Sky Atlantic, and Sky Cinema. Sky is also one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amstrad
Amstrad plc was a British consumer electronics company, founded in 1968 by Alan Sugar. During the 1980s, the company was known for its Home computer, home computers beginning with the Amstrad CPC and later also the ZX Spectrum range after the Sinclair Research, Sinclair deal, which led it to have a substantial share of the home computer market in Britain. In the following decade it shifted focus towards communication technologies, and its main business during the 2000s was the manufacture of satellite television set-top boxes for Sky UK, Sky, which Amstrad had started in 1989 as the then sole supplier of the emerging Sky TV service. Headquartered in Brentwood, Essex, Brentwood, the company was listed on the London Stock Exchange from 1980 to 2008, the year when Sugar stepped down after 40 years. After acquiring Betacom and Viglen, Amstrad was broken up in 1997 but the name was soon revived when successor Betacom plc renamed itself to Amstrad plc. Amstrad was a FTSE 100 Index co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pace Plc
Pace plc was a British company which developed set-top boxes (STBs), advanced residential gateways, software and services for the pay-TV and broadband services industry. Pace's customers included cable, telco, satellite and IPTV operators. The company was listed on the London Stock Exchange until December 2015, when the company received the last of the regulatory clearances needed to allow a merger with Arris Group to proceed. In 2019, Arris was subsequently acquired by network infrastructure provider CommScope. History The company was founded by Yorkshire born businessmen Barry Rubery, David Hood and Robert Fleming in 1982, taking the name ''Pace Micro Supplies'' in 1983, eventually being renamed to ''Pace Micro Technology plc'' in 1987. It introduced the first low cost commercially available modems in 1985. In 1987, it started selling its first analogue satellite set top receivers. In 1996, it introduced the world's first DVB decoders, for Australian satellite company ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio (commonly 16:9) in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same Bandwidth (signal processing), bandwidth as a single analog channel, and provides many new features that analog television cannot. A digital television transition, transition from analog to digital broadcasting began around 2000. Different digital television broadcasting st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG
The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by International Organization for Standardization, ISO and International Electrotechnical Commission, IEC that sets standards for media coding, including compression coding of audio compression (data), audio, video compression, video, graphics, and Compression of Genomic Sequencing Data, genomic data; and transmission and Container format (digital), file formats for various applications.John Watkinson, ''The MPEG Handbook'', p. 1 Together with Joint Photographic Experts Group, JPEG, MPEG is organized under ISO/IEC JTC 1/ISO/IEC JTC 1/SC 29, SC 29 – ''Coding of audio, picture, multimedia and hypermedia information'' (ISO/IEC Joint Technical Committee 1, Subcommittee 29). MPEG formats are used in various multimedia systems. The most well known older MPEG media formats typically use MPEG-1, MPEG-2, and MPEG-4 AVC media coding and MPEG-2 systems MPEG transport stream, transport streams an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artifact (error)
In natural science and signal processing, an artifact or artefact is any error in the perception or representation of any information introduced by the involved equipment or technique(s). Statistics In ''statistics'', statistical artifacts are apparent effects that are introduced inadvertently by methods of data analysis rather than by the process being studied. Computer science In ''computer science'', digital artifacts are anomalies introduced into digital signals as a result of digital signal processing. Microscopy In ''microscopy'', visual artifacts are sometimes introduced during the processing of samples into slide form. Econometrics In ''econometrics'', which focuses on computing relationships between related variables, an artifact is a spurious finding, such as one based on either a faulty choice of variables or an over-extension of the computed relationship. Such an artifact may be called a ''statistical artifact''. For instance, imagine a hypothetical finding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
