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Inter-satellite Service
Inter-satellite service (also: inter-satellite radiocommunication service) is – according to ''Article 1.22'' of the International Telecommunication Union's (ITU) Radio Regulations (RR)ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.22, definition: ''inter-satellite service / inter-satellite radiocommunication service'' – defined as ''«A radiocommunication service providing links between artificial satellites.'' Classification In accordance with ''ITU Radio Regulations'' (article 1) variations of this ''radiocommunication service'' are classified as follows: * Fixed service (article 1.20) ** Fixed-satellite service (article 1.21) ** (article 1.22) ** Earth exploration-satellite service (article 1.51) *** Meteorological-satellite service (article 1.52) Satellites Inter-satellite radiocommunications satellites * U.S. Tracking and Data Relay Satellite * Artemis (satellite) * European Data Relay System * Indian Data Relay Satellite System * Luc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Data Relay Satellite System
Indian Data Relay Satellite System or IDRSS is a planned Indian constellation of Inter-satellite communications satellites. It is planned to initially comprise two satellites, CMS-04 (formerly IDRSS-1) & IDRSS-2 in geostationary orbit. It will facilitate relay of information between various Indian spacecraft, in-flight launch vehicle monitoring and assist Indian Human Spaceflight Programme. Objectives A Data Relay Satellite System (DRSS) facilitates continuous real-time communication between Low Earth orbit bound spacecraft to the ground station as well as inter-satellite communication. Such a satellite in geostationary orbit can track a low altitude spacecraft up to almost half of its orbit. India operates one of world's largest remote sensing satellites systems. Visibility of these satellites is not more than 10-15 minutes in a day and sometimes even lower. The IDRSS satellites, one opposite to each half of earth in GEO, can see about 80 per cent of the area where Indian remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Communication In Space
Laser communication in space is the use of free-space optical communication in outer space. Communication may be fully in space (an inter-satellite laser link) or in a ground-to-satellite or satellite-to-ground application. The main advantage of using laser communications over radio waves is increased bandwidth, enabling the transfer of more data in less time. In outer space, the communication range of free-space optical communication is currently of the order of hundreds of thousands of kilometers,. Laser-based optical communication has been demonstrated between the Earth and Moon and it has the potential to bridge interplanetary distances of millions of kilometers, using optical telescopes as beam expanders. Demonstrations and tests Before 1990 On 20 January 1968, the television camera of the Surveyor 7 lunar lander successfully detected two argon lasers from Kitt Peak National Observatory in Arizona and Table Mountain Observatory in Wrightwood, California. 1991- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless Mesh Network
A wireless mesh network (WMN) is a communications network made up of radio nodes organized in a mesh topology. It can also be a form of wireless ad hoc network. Chai Keong Toh Ad Hoc Mobile Wireless Networks, Prentice Hall Publishers, 2002. A mesh refers to rich interconnection among devices or nodes. Wireless mesh networks often consist of mesh clients, mesh routers and gateways. Mobility of nodes is less frequent. If nodes constantly or frequently move, the mesh spends more time updating routes than delivering data. In a wireless mesh network, topology tends to be more static, so that routes computation can converge and delivery of data to their destinations can occur. Hence, this is a low-mobility centralized form of wireless ad hoc network. Also, because it sometimes relies on static nodes to act as gateways, it is not a truly all-wireless ad hoc network. Mesh clients are often laptops, cell phones, and other wireless devices. Mesh routers forward traffic to and from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Station
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 br ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starlink
Starlink is a satellite internet constellation operated by SpaceX, providing satellite Internet access coverage to 45 countries. It also aims for global mobile phone service after 2023. SpaceX started launching Starlink satellites in 2019. As of December 2022, Starlink consists of over 3,300 mass-produced small satellites in low Earth orbit (LEO), which communicate with designated ground transceivers. In total, nearly 12,000 satellites are planned to be deployed, with a possible later extension to 42,000. SpaceX announced reaching more than one million subscribers in December 2022. The SpaceX satellite development facility in Redmond, Washington houses the Starlink research, development, manufacturing, and orbit control teams. The cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in May 2018 to be at least US$10 billion. SpaceX expects more than $30 billion in revenue by 2025 from its satellite constellation, while revenu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium Satellite Constellation
The Iridium satellite constellation provides L band voice and data information coverage to satellite phones, pagers and integrated transceivers over the entire surface of Earth. Iridium Communications owns and operates the constellation, additionally selling equipment and access to its services. It was conceived by Bary Bertiger, Raymond J. Leopold and Ken Peterson in late 1987 (in 1988 protected by patents Motorola filed in their names) and then developed by Motorola on a fixed-price contract from July 29, 1993, to November 1, 1998, when the system became operational and commercially available. The constellation consists of 66 active satellites in orbit, required for global coverage, and additional spare satellites to serve in case of failure. Satellites are placed in low Earth orbit at a height of approximately and inclination of 86.4°. The nearly polar orbit and communication between satellites via Ka band inter-satellite links provide global service availability (inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tianlian I
Tianlian (Simplified Chinese: 天链, Traditional Chinese: 天鏈, English: ''Sky Link'') also known as CTDRS, is a Chinese data relay communication satellite constellation. The constellation serves to relay data from ground stations to spacecraft and rockets, most significantly China's crewed spaceflight program. The system currently consists of seven satellites in two generations, with the first satellite being launched in 2008. Mission Tianlian is used to provide real-time communications between orbiting satellites and ground control stations. The Chinese tracking and data relay satellites were developed by the China Academy of Space Technology (CAST) and it is similar to the American Tracking and Data Relay Satellite System (TDRSS) in concept. The system is designed to support near-real-time communications between orbiting spacecraft and ground control, as well as complement the ground-based space tracking and telemetry stations and ships in tracking spacecraft. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luch (satellite)
The ''Luch'' (russian: Луч; lit. ''Ray'') Satellite Data Relay Network (SDRN), also referred to as ''Altair'' and ''Gelios'', is a series of geosynchronous Russian relay satellites, used to transmit live TV images, communications and other telemetry from the Soviet/Russian space station '' Mir'', the Russian Orbital Segment (ROS) of the International Space Station and other orbital spacecraft to the Earth, in a manner similar to that of the US Tracking and Data Relay Satellite System. First generation The first generation of satellites was created by NPO-PM using the satellite platform KAUR-4 (its first use) and had the code name "Altair" (index GUKOS - 11F669). The system was conceived as part of the second generation of the Global Satellite Data Relay Network (Глобальная Космическая Командно-Ретрансляционная система (GKKRS)) and was developed by decree of the Soviet Council of Ministers of February 17, 1976 ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Data Relay System
The European Data Relay System (EDRS) system is a European constellation of GEO satellites that relay information and data between satellites, spacecraft, UAVs, and ground stations. The first components (a payload and dedicated GEO satellite) were launched in 2016 and 2019. Purpose and context The designers intend the system to provide almost full-time communication, even with satellites in low Earth orbit that often have reduced visibility from ground stations. It makes on-demand data available to, for example, rescue workers who want near-real-time satellite data of a crisis region. There are a number of key services that will benefit from this system's infrastructure: * Earth Observation applications in support of time-critical and/or data-intensive services; e.g., change detection, environmental monitoring. * Government and security services that need images from key European space systems such as Global Monitoring for Environment and Security. * Emergency response and crisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telecommunication Union
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Union, making it the oldest UN agency. The ITU was initially aimed at helping connect telegraphic networks between countries, with its mandate consistently broadening with the advent of new communications technologies; it adopted its current name in 1932 to reflect its expanded responsibilities over radio and the telephone. On 15 November 1947, the ITU entered into an agreement with the newly created United Nations to become a specialized agency within the UN system, which formally entered into force on 1 January 1949. The ITU promotes the shared global use of the radio spectrum, facilitates international cooperation in assigning satellite orbits, assists in developing and coordinating worldwide technical standards, and works to improve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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