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Co-location (satellite)
Co-location is the placing of two or more geostationary communications satellites in orbit, in close proximity so that to reception equipment on the ground they 'appear' to occupy a single orbital position. The technique as applied to a group of TV satellites from a single operator was pioneered by SES with the Astra satellites at 19.2°E. Satellite separation Communications satellites' orbital positions are normally spaced apart along the geostationary orbit to provide for frequency reuse for both uplink and downlink transmissions. By separating adjacent satellites by a distance greater than the at-orbit beamwidth of the uplink antennas, the same carrier frequencies can be used to uplink to both satellites without interference. Similarly, a sufficient separation so that the beamwidth of the receiving dishes on the ground can distinguish one satellite from its neighbours, allows the same frequency spectrum to be used for adjacent satellite downlinks. Communications satellites ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary
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 altitude above Earth's equator ( in radius from Earth's center) and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them but can be pointed permanently at the position in the sky where the sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1B
Astra 1B was the second of the Astra communications satellites launched and operated by SES (Société Européenne des Satellites) to add extra capacity to the satellite television (direct broadcasting) services from 19.2° East, serving Germany, the United Kingdom and Ireland. Satcom K3 SES bought the satellite in 1989 from failed direct broadcast satellite (DBS) company Crimson Satellite Associates while still under construction by GE Astro Space (as Satcom K3). Twelve years later, in 2001, SES acquired GE Americom, which originally was to operate the Satcom K3 satellite (and was itself the result of General Electric's purchase of RCA Corporation in 1986) and renamed it "SES Americom". It was merged with SES New Skies to form SES World Skies before the company was merged into its parent company, SES S.A. in 2011. Mission On 4 June 1991, Astra 1B suffered an attitude control failure, causing minor drift in north–south direction, meaning that it became difficult to obt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Above (book)
''High Above - The untold story of Astra, Europe's leading satellite company'' is a book describing the development of the European satellite provider SES, published in 2010 on the occasion of the company's 25th anniversary by Broadgate Publications in Richmond, London, United Kingdom. It is a large "coffee table" style book (32 x 24 cm) of 239 pages with hundreds of photographs. Outline ''High Above'' tells the story of Société Européenne des Satellites, and how the company managed to overcome technical, political, and commercial obstacles to become one of the world's leading satellite operators. It is the story of the Luxembourg-based satellite provider and the growth of European satellite television, the history of recent developments of the European television and media industry, and their context in the wider development of television and space technology. ''High Above'' chronicles the emergence of television as the dominant information and entertainment mediu ... [...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] |
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 altitude above Earth's equator ( in radius from Earth's center) and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them but can be pointed permanently at the position in the sky where the sat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend word, blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a Transponder (aeronautics), flight transponder is an automated transceiver in an aircraft that emits a coded identifying signal in response to an interrogating received signal. In a communications satellite, a Transponder (satellite communications), satellite transponder receives signals over a range of uplink frequencies, usually from a satellite ground station; the transponder amplifies them, and re-transmits them on a different set of downlink frequencies to receivers on Earth, often without changing the content of the received signal or signals. Satellite/broadcast communications A communications satellite’s Communication channel, channels are called transponders because each is a separate transceiver or repeater. With digital video d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 28
Astra may refer to: People * Astra (name) Places * Astra, Chubut, a village in Argentina * Astra (Isauria), a town of ancient Isauria, now in Turkey * Astra, one suggested name for a hypothetical fifth planet that became the asteroid belt Entertainment * Astra (Marvel Comics), the name of two otherwise unrelated Marvel Comics characters from 1977 and 1999, respectively * Astra (DC Comics) ''Supergirl'' is an American television series developed by Greg Berlanti, Ali Adler, and Andrew Kreisberg based on the characters created by Jerry Siegel and Joe Shuster in the Superman franchise and Al Plastino and Otto Binder's character Sup ... * Astra (film), ''Astra'' (film), a 2012 Bengali film * Australian Subscription Television and Radio Association * ASTRA Awards, annual awards presented by the Australian subscription television industry * Astra, a character in the TV series ''Ultraman Leo#Astra, Ultraman Leo'' Music * Astra Chamber Music Society, a Melbourne, Australia conce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1H
Astra 1H is one of the Astra communications satellites owned and operated by SES. History SES ordered its Hughes 601HP satellite, in 1995 for Astra 1H. Launch Astra-1H was launched on 18 June 1999 at 01:49:30 UTC, by a Proton-K / DM-2M launch vehicle, from Site 81/23 at the Baikonur Cosmodrome in Kazakhstan. It was maneuvered into a geostationary orbit at 19.2° East of longitude Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter l .... References {{Orbital launches in 1999 Astra satellites Satellites of Luxembourg Spacecraft launched in 1999 1999 in spaceflight 1999 in Luxembourg Satellites using the BSS-601 bus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1G
Astra 1G is one of the Astra communications satellites owned and operated by SES. History SES ordered its Hughes 601HP satellite, in 1994 for Astra 1G. Launch Astra-1G was launched on 2 December 1997 at 23:10:37 UTC, by a Proton-K / DM-2M launch vehicle, from Site 81/23 at the Baikonur Cosmodrome in Kazakhstan. It was maneuvered into a geostationary orbit and at 19.2° East of longitude. See also * SES SES, S.E.S., Ses and similar variants can refere to: Business and economics * Socioeconomic status * Scottish Economic Society, a learned society in Scotland * SES, callsign of the TV station SES/RTS (Mount Gambier, South Australia) * SES S.A., ... (satellite operator) * Astra (satellite family) References Astra satellites Satellites of Luxembourg Spacecraft launched in 1997 1997 in spaceflight 1997 in Luxembourg Satellites using the BSS-601 bus {{communications-satellite-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1F
Astra 1F is one of the Astra communications satellites in geostationary orbit owned and operated by SES. It was launched in April 1996 to the Astra 19.2°E orbital slot initially to provide digital television and radio for direct-to-home (DTH) across Europe. The satellite originally provided two broadcast beams, of horizontal and vertical polarisation, for Fixed Service Satellite (FSS) (10.70-10.95 GHz) and for Broadcast Satellite Service (BSS) (11.70-12.10 GHz) frequency bands. The FSS beams provide footprints that cover essentially the same area of Europe – northern, central and eastern Europe, including Spain and northern Italy – while the BSS horizontal beam excludes Spain and extends further east, and the BSS vertical beam includes Spain and more of southern Italy but does not extend so far east. Within the footprints, television signals are usually received with a 60–80 cm dish. See also * Astra satellite family * SES satellite operator * SES Broad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1E
Astra 1E is one of the Astra communications satellites in geostationary orbit owned and operated by SES. It was launched in October 1995 to the Astra 19.2°E orbital slot initially to provide digital television and radio for direct-to-home (DTH) across Europe. Astra 1E was the first Astra satellite to be dedicated to digital television broadcasting and it carried many of the first digital television channels from networks broadcasting to France, Germany, and other European countries in the 1990s. The satellite originally provided two broadcast beams, of horizontal and vertical polarisation, for Fixed Service Satellite (FSS) (10.70-10.95 GHz) and for Broadcast Satellite Service (BSS) (11.70-12.10 GHz) frequency bands. The FSS beams provide footprints that cover essentially the same area of Europe – northern, central and eastern Europe, including Spain and northern Italy – while the BSS horizontal beam excludes Spain and extends further east, and the BSS vertical beam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1D
Astra 1D is a geostationary communications satellite launched in 1994 by the Société Européenne des Satellites (SES). , the craft remains in service for occasional use. Astra 1D was the fourth, and under original plans, last Astra communications satellite from SES. It was launched to SES' original solitary operational position at 19.2° East, and was intended as an in-orbit spare for Astra's Astra 1A, 1B and 1C and to carry digital TV transmissions. However, development of digital reception equipment in Europe was not sufficiently advanced for Astra 1D to be SES' first digital satellite (the later Astra 1E fulfilled that role) and demand for additional capacity for both British and German television channels led to 12 of the satellite's transponders being leased to broadcast analogue TV channels before the satellite had been launched. History After launch to 19.2° East, Astra 1D served two periods as a spare at the Astra 28.2°E position colocated with Astra 2A, for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
