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JCSAT-2A
JCSAT-2A, known as JCSAT-8 before launch, is a geostationary communications satellite operated by SKY Perfect JSAT Group (JSAT) which was designed and manufactured by Boeing Satellite Systems on the BSS-601 platform. It has Ku-band and C-band payload and was used to replace JCSAT-2 at the 154° East longitude. It covers Japan, East Asia, Australia and Hawaii. Satellite description The spacecraft was designed and manufactured by Boeing Satellite Systems on the BSS-601 satellite bus. It had a launch mass of a power production of 3.7 kW and an 11-year design life. Stowed for launch it measured , with its solar panels and antennas deployed it measured . Its payload is composed of sixteen 57 MHz Ku-band plus eleven 36 MHz and five 54 MHz C-band transponders, for a total bandwidth of 1,578 MHz. Its high-power amplifiers had an output power of 120 watts on Ku-band and 34 watts on C-band. The Ku-band footprint covers only Japan, while the C-band beams cover Jap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JCSAT-5A
JCSAT-5A or N-STAR d, known as JCSAT-9 before launch, is a geostationary communications satellite operated by SKY Perfect JSAT Group (JSAT) which was designed and manufactured by Lockheed Martin on the A2100 platform. Satellite description The spacecraft was designed and manufactured by Lockheed Martin on the A2100-AX satellite bus. It had a launch mass of and a 12-year design life. It would provide communications services throughout Japan and Asia and for NTT DoCoMo. As most satellites based on the A2100-AX platform, it uses a LEROS-1C liquid apogee engine (LAE) for orbit raising. Its solar panels span when fully deployed and, with its antennas in fully extended configuration it is wide. Its payload is composed of eight 54 MHz and twelve 36 MHz Ku-band transponders, twenty 36 MHz C-band transponders and one S-band beam. The Ku-band transponders have a TWTA output power of 110 watts, the C-band of 45 watts and the S beam of 130 watts. History On 30 April ... [...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] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellites In Geostationary Orbit
Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquiry studying them. There are many disagreements about its precise definition. John Peters argues that the difficulty of defining communication emerges from the fact that communication is both a universal phenomenon and a specific discipline of institutional academic study. One definitional strategy involves limiting what can be included in the category of communication (for example, requiring a "conscious intent" to persuade). By this logic, one possible definition of communication is the act of developing meaning among entities or groups through the use of sufficiently mutually understood signs, symbols, and semiotic conventions. An important distinction is between verbal communication, which happens through the use of a language, and non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hughes Aircraft Company
The Hughes Aircraft Company was a major American aerospace and defense contractor founded on February 14, 1934 by Howard Hughes in Glendale, California, as a division of Hughes Tool Company. The company was known for producing, among other products, the Hughes H-4 Hercules ''Spruce Goose'' aircraft, the atmospheric entry probe carried by the ''Galileo'' spacecraft, and the AIM-4 Falcon guided missile. Hughes Aircraft was founded to construct Hughes' H-1 Racer world speed record aircraft, and it later modified aircraft for his transcontinental and global circumnavigation speed record flights. The company relocated to Culver City, California, in 1940 and began manufacturing aircraft parts as a subcontractor. Hughes attempted to mold it into a major military aircraft manufacturer during World War II; however, its initial military projects ended in failure, with millions of dollars in U.S. government funds expended but only three aircraft actually built, resulting in a highly publi ... [...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] |
High-power Amplifier
In electronics, the figures of merit of an amplifier are numerical measures that characterize its properties and performance. Figures of merit can be given as a list of specifications that include properties such as gain, bandwidth, noise and linearity, among others listed in this article. Figures of merit are important for determining the suitability of a particular amplifier for an intended use. Gain The gain of an amplifier is the ratio of output to input power or amplitude, and is usually measured in decibels. When measured in decibels it is logarithmically related to the power ratio: ''G''(dB)=10 log(''Pout'' /''Pin''). RF amplifiers are often specified in terms of the maximum ''power gain'' obtainable, while the voltage gain of audio amplifiers and instrumentation amplifiers will be more often specified. For example, an audio amplifier with a gain given as 20 dB will have a ''voltage gain'' of ten. The use of voltage gain figure is appropriate when the amplifier's in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder (satellite Communications)
A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas. It is mainly used in satellite communication to transfer the received signals. A transponder is typically composed of: * an input band-limiting device (an input band-pass filter), * an input low-noise amplifier (LNA), designed to amplify the signals received from the Earth station (normally very weak, because of the large distances involved), * a frequency translator (normally composed of an oscillator and a frequency mixer) used to convert the frequency of the received signal to the frequency required for the transmitted signal, * an output band-pass filter, * a power amplifier (this can be a traveling-wave tube or a solid-state amplifier). Most communication satellites are radio relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Most transponders operate on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Bus
A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-derived satellites are usually customized to customer requirements, for example with specialized sensors or transponders, in order to achieve a specific mission. They are commonly used for geosynchronous satellites, particularly communications satellites, but are also used in spacecraft which occupy lower orbits, occasionally including low Earth orbit missions. Examples Some satellite bus examples include: * Boeing DS&S 702 * Lockheed Martin Space Systems A2100 * Alphabus * INVAP ARSAT-3K * Airbus D&S Eurostar * ISRO's I-1K, I-2K, I-3K, I-4K, I-6K, and Indian Mini Satellite bus * NASA Ames MCSB * SSL 1300 * Orbital ATK GEOStar * Mitsubishi Electric DS2000 * Spacecraft bus of the James Webb Space Telescope * SPUTNIX TabletSat * ... [...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] |
