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Astra 2C
Astra 2C is one of the Astra communications satellites owned and operated by Société Eurpéenne des Satellites. Designed to join Astra 2A and Astra 2B at the Astra 28.2°E orbital position providing digital television and radio broadcast services to the United Kingdom and Ireland, the satellite was first used after launch in 2001 at 19.2° East for pan-European coverage. The satellite provides one broadcast beam with horizontal and vertical polarisation, across a single footprint covering the areas of Central and Eastern Europe, Scandinavia, the Iberian Peninsula and Canary Islands. TV signals can be received with a 50 cm dish across the majority of the British Isles with a 60 cm dish required in the extreme north and west. Astra 2C can also provide backup capacity, substituting for one or more transponders across the 10.70-12.20 GHz broadcast range used by Astra satellites in the Astra 19.2°E and Astra 28.2°E orbital positions. History Although origina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku Band
The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the original NATO K band, which was split into three bands (Ku, K, and Ka) because of the presence of the atmospheric water vapor resonance peak at 22.24 GHz, (1.35 cm) which made the center unusable for long range transmission. In radar applications, it ranges from 12 to 18 GHz according to the formal definition of radar frequency band nomenclature in IEEE Standard 521–2002. Ku band is primarily used for satellite communications, most notably the downlink used by direct broadcast satellites to broadcast satellite television, and for specific applications such as NASA's Tracking Data Relay Satellite used for International Space Station (ISS) communications and SpaceX Starlink satellites. Ku band satellites are also used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Europe
Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the area's history. The concept of "Central Europe" appeared in the 19th century. Central Europe comprised most of the territories of the Holy Roman Empire and those of the two neighboring kingdoms of Poland and Hungary. Hungary and parts of Poland were later part of the Habsburg monarchy, which also significantly shaped the history of Central Europe. Unlike their Western European (Portugal, Spain et al.) and Eastern European (Russia) counterparts, the Central European nations never had any notable colonies (either overseas or adjacent) due to their inland location and other factors. It has often been argued that one of the contributing causes of both World War I and World War II was Germany's lack of original overseas colonies. After World War ... [...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, 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. Footprint maps usually show either the estimated minimum satellite dish diameter required or the signal strength in each area measured in dBW. 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 Federal State Unitary Enterprise Satellite Communications (russian: ФГУП «Космическая связь») or Russian Satellite Communications Company is the main state operator of communications satellites. It is the Russian operator ... satellites Link to satellite footprintsfr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarization (waves)
Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string ''(see image)''; for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, and transverse sound waves (shear waves) in solids. An electromagnetic wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Broadcasting
Radio broadcasting is transmission of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in satellite radio the radio waves are broadcast by a satellite in Earth orbit. To receive the content the listener must have a broadcast radio receiver (''radio''). Stations are often affiliated with a radio network which provides content in a common radio format, either in broadcast syndication or simulcast or both. Radio stations broadcast with several different types of modulation: AM radio stations transmit in AM ( amplitude modulation), FM radio stations transmit in FM (frequency modulation), which are older analog audio standards, while newer digital radio stations transmit in several digital audio standards: DAB (digital audio broadcasting), HD radio, DRM ( Digital Radio Mondiale). Television broadcasting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using 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 of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same bandwidth as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 2B
Astra 2B is one of the Astra communications satellites owned and operated by Société Européenne des Satellites. Launched in September 2000 to join Astra 2A at the Astra 28.2°E orbital position providing digital television and radio broadcast services to the United Kingdom and Ireland, the satellite has also served at the Astra 19.2°E and the Astra 31.5°E positions. History The satellite provides two broadcast beams, each with horizontal and vertical polarisation, across two footprints - 2B North (covering Central Europe and Scandinavia) and 2B South (covering Central Europe and the Iberian Peninsula and Canary Islands). While at 28.2° East, television signals could be received with a 43 cm dish across the majority of the British Isles with a 60 cm dish required in the extreme north and west, although the official footprint maps now show a 60 cm dish as required across all of Western Europe. At 28.2° East, 17 transponders on Astra 2B were used by BSky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 2A
Astra 2A is one of the Astra communications satellites owned by Société Européenne des Satellites. Launched in 1998 into the 28.2° East orbital position, half its expected end-of-life capacity of 28 transponders were pre-booked by BSkyB, who utilised it to launch their new Sky Digital service. In March 2015, the satellite has been deactivated and relocated to 113.5° East. History The satellite suffered pre-launch technical issues with its apogee motors and was moved to a launch by the Proton-K / DM-03 rather than the Ariane 5, as the Proton can inject directly in geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ... (GEO). When positioned at 28.2 East, it joined DFS Kopernikus, DFS Kopernikus-1, which served mainly Eastern Europe. The satellite was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra (satellites)
Astra is the brand name for a number of geostationary communication satellites, both individually and as a group, which are owned and operated by SES S.A., a global satellite operator based in Betzdorf, in eastern Luxembourg. The name is also used to describe the pan-European broadcasting system provided by these satellites, the channels carried on them, and even the reception equipment. At the time of the launch of the first Astra satellite, Astra 1A in 1988, the satellite's operator was known as Société Européenne des Satellites. In 2001 SES Astra, a newly formed subsidiary of SES, operated the Astra satellites and in September 2011, SES Astra was consolidated back into the parent company, which by this time also operated other satellite families such as AMC, and NSS. Astra satellites broadcast 2600 digital television channels (675 in high definition) via five main satellite orbital positions to households across Asia, Australia, Africa, Americas, Europe, New Zealand, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 3A
Astra 3A is one of the Astra communications satellites owned and operated by Société Européenne des Satellites, launched in March 2002 to the Astra 23.5°E orbital position to provide digital television and radio for direct to home (DTH) and cable, multimedia and interactive services, corporate networks, and occasional and other business services to Europe. The satellite provides two broadcast beams, of horizontal and vertical polarisation, across two footprints that covered essentially the same areas of Europe – principally the countries of central Europe. History Astra 3A was launched to provide follow-on capacity to replace the DFS Kopernikus-3 satellite and deliver additional capacity for the Benelux countries and central Europe, to create SES-Astra's third major European satellite hotspot after Astra 19.2°E and Astra 28.2°E with access to channels at both positions using a single dish fitted with a monoblock Duo LNB. In that role, television signals could be re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
