|
X Band Satellite Communication
X band or SHF Satellite Communication is widely used by military forces for beyond line of sight communications. X band is used because it provides a compromise between the characteristics of different frequency bands which is particularly suited to the needs of military users. The characteristics include interference and rain resilience, terminal size, data rates, remote coverage and whether it is reserved for governmental use. Characteristics of the SHF frequency band Frequency x Band Satellite Communication operates in the part of the X band or Super High Frequency (SHF) spectrum which is designated by the International Telecommunication Union (ITU) for satellite communication, which is those frequencies in the range 7.25 GHz to 7.75 GHz (Space to Earth) and 7.9 GHz to 8.4 GHz (Earth to Space). The ITU Frequency allocation defines the primary use of this spectrum as Fixed satellite service (FSS) and a portion to Mobile Satellite Services (MSS), primaril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Band
The X band is the designation for a band of frequencies in the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of the X band is rather indefinitely set at approximately 7.0–11.2 GHz. In radar engineering, the frequency range is specified by the Institute of Electrical and Electronics Engineers (IEEE) as 8.0–12.0 GHz. The X band is used for radar, satellite communication, and wireless computer networks. Radar X band is used in radar applications including continuous-wave, pulsed, single- polarization, dual-polarization, synthetic aperture radar, and phased arrays. X band radar frequency sub-bands are used in civil, military, and government institutions for weather monitoring, air traffic control, maritime vessel traffic control, defense tracking, and vehicle speed detection for law enforcement. X band is often used in modern radars. The shorter wavelengths of the X band allow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XTAR-EUR
The XTAR-EUR is a communication satellite developed by Spain and the United States and in order to provide a secure channel over the Indian Ocean. It was originally operated by XTAR and Hisdesat. In year 2020 Hisdesat bought 100% stake on the satellite. Its launch short after the Spainsat is part of an effort to strengthen Spain's communication ties with allied countries around the globe, particularly in maters of national security (defense, disaster relief...). Body The satellite is based on the Space Systems/Loral LS-1300 model. Consequently, it is shaped like a box (5.4 x 2.9 x 2.2 m) with a total weight of 1412 kg (3631 kg at launch). The sides of the box contain two retractable solar panels (providing up to 3.6 kW of power) while the lower base (facing anti-radial direction) holds the communication module. This module operates on the X band (compatible with SATCOM systems employed by NATO) and consists of 12 X-band transponders of 72 MHz broadband ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called transponders. Many satellites use a standardized bus to save cost and work, the most popular of which is small CubeSats. Similar satellites can work together as a group, forming constellations. Because of the high launch cost to space, satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to avoid orbital decay by the atmosphere. Satellites can then change or maintain the orbit by propuls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Communications
Military communications or military signals involve all aspects of communications, or conveyance of information, by armed forces. Military communications span from pre-history to the present. The earliest military communications were delivered by runners. Later, communications progressed to visual and audible signals, and then advanced into the electronic age. Examples from ''Jane's Military Communications'' include text, audio, facsimile, tactical ground-based communications, naval signalling, terrestrial microwave, tropospheric scatter, satellite communications systems and equipment, surveillance and signal analysis, security, direction finding and jamming.IHS Jane'sMilitary Communications Retrieved 2012-01-23. History In past centuries communicating a message usually required someone to go to the destination, bringing the message. Thus, the term ''communication'' often implied the ability to transport people and supplies. A place under siege was one that lost communicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Communications
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 satelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Segment
A ground segment consists of all the ground-based elements of a space system used by operators and support personnel, as opposed to the space segment and user segment. The ground segment enables management of a spacecraft, and distribution of payload data and telemetry among interested parties on the ground. The primary elements of a ground segment are: * Ground (or Earth) stations, which provide radio interfaces with spacecraft * Mission control (or operations) centers, from which spacecraft are managed * Remote terminals, used by support personnel * Spacecraft integration and test facilities * Launch facilities * Ground networks, which allow for communication between the other ground elements These elements are present in nearly all space missions, whether commercial, military, or scientific. They may be located together or separated geographically, and they may be operated by different parties. Some elements may support multiple spacecraft simultaneously. Elements Groun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SICRAL 1B
SICRAL 1B is a military communications satellite built by Thales Alenia Space for Italian Armed Forces. It is a dual-use spacecraft: Telespazio will use some of the satellite's transmission capacity and some will be used by the Italian defense ministry and NATO. The spacecraft is based on the Italsat 3000 bus and includes one EHF/Ka band, three UHF-band and five active SHF-band transponders. It is designed to be operable for 13 years. Construction Thales Alenia Space was the prime contractor for development and construction of the SICRAL 1B satellite. Launch On April 20, 2009 Sea Launch used a Zenit-3SL to carry SICRAL 1B into a geosynchronous transfer orbit. Liftoff from the Ocean Odyssey LP ''Odyssey'' is a self-propelled semi-submersible mobile spacecraft launch platform converted from a mobile drilling rig in 1997. The vessel was used by Sea Launch for equatorial Pacific Ocean launches. She works in concert with the assembly ... launch platform took place at 08:16 GMT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hisdesat
Hisdesat (, 'Hisdesat Strategic Services') is a Spanish company created in 2001 by Hispasat (43%), Ingeniería y Servicios Aeroespaciales (30%), EADS CASA (15%, now Airbus), Indra Sistemas (7%) and SENER (5%) with initial investment of 415 million euros. Satellites Satellites: * Spainsat, secure communications, GEO * XTAR-EUR, secure communications, GEO * Paz, Earth observation, SSO, synthetic-aperture radar (SAR), X-band The X band is the designation for a band of frequencies in the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of the X band is rather indefinitely set at approxi ... * Spainsat NG I, secure communications, GEO * Spainsat NG II, secure communications, GEO Launched satellites Other sources: See also * Hispasat, another Spanish satellite operator References External links * {{Space program of Spain Communications satellite operators Direct broadcas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spainsat
Spainsat is a Spanish telecommunications satellite used for military and government communications. It allows telecommunications the different missions of the Spanish Armed forces abroad by providing coverage on a wide area of the world ranging from the United States and South America to the Middle East, including Africa and Europe. Overview The satellite belongs to Hisdesat (Spanish company participated by Hispasat (43%), Ingeniería y Servicios Aeroespaciales (30%), Airbus (15%), Indra Espacio (7%) and Sener (5%)), and its initial investment was 415 million euros. It was built by Space Systems Loral in California United States, with an expected useful life of at least 15 years. Its takeoff mass was about 3,700 kilograms. It is instrumented with several transponders in the X band and one in the K military band. It is situated on a geostationary orbit at 36,000 kilometres of altitude, 30 degrees west, over the Atlantic Ocean. The satellite provides coverage to humanitaria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hispasat
Hispasat is the operating company for a number of Spanish communications satellites that cover the Americas, Europe and North Africa from orbital positions 30.0° West and 61.0° West. It was formed in 1989 and its activities include provision of communication services in the commercial and government sectors (corporate networks, advanced telecommunications services, telephony, videoconferencing, etc.). Hispasat's fleet of satellites broadcast more than 1250 television channels and radio stations to more than 30 million homes, as well as providing services such as broadband to mobile telephones and landlines. The first Hispasat satellite sent into orbit was Hispasat 1A, which was launched on 11 September 1992 on board an Ariane 4 launch vehicle from the Centre Spatial Guyanais near Kourou in French Guiana. It was put into geostationary orbit at 30° West, which is the location of all their subsequent satellites serving Spain and Europe. The Amazonas satellites (61° West) wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XTAR
XTAR, LLC is a commercial satellite operator exclusively providing services in the X band frequency range, which is the communications cornerstone of today's military, diplomatic, humanitarian and emergency disaster response operations. A privately owned and operated company, XTAR supports the critical satellite communications needs of governments around the world through its two X-band payloads. The XTAR satellites were designed and built by private financing. Loral Space & Communications, Inc. owns the majority share. XTAR is headquartered in Ashburn, VA. With its high-powered 72 MHz transponders and global, fixed and steerable beams, XTAR provides over 4 GB of secure X-band capacity with coverage from Denver east to Singapore. The system can accommodate massive wideband data requirements and provides overlapping coverage with regional redundancy for increased service and reliability. XTAR bandwidth is not application-specific; it can support and transmit to any one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Space Segment
The space segment of an artificial satellite system is one of its three operational components (the others being the user and ground segments). It comprises the satellite or satellite constellation and the uplink and downlink satellite links. The overall design of the payload, satellite, ground segment, and end-to-end system is a complex task. Satellite communications payload design must be properly coupled with the capabilities and interaction with the spacecraft bus that provides power, stability and environmental support to the payload. Telecommunications satellites Geostationary Earth orbit (GEO) supports businesses in satellite television and radio broadcasting, as well as data and mobile communications. The medium Earth orbit (MEO) and low Earth orbit (LEO) configurations can also be used for various applications. A communications satellite is composed of a communications payload (repeater and antenna) and supporting spacecraft bus (including solar arrays and batteries, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
