4G

Similar topics in Freebase

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  Automatic Dependent Surveillance-Broadcast

  Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance technology for tracking aircraft as part of the Next Generation Air Transportation System (NextGen). The United States will require the majority of aircraft operating within its airspace to be equipped with some form of ADS-B Out...
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  Echelon

  ECHELON is a name used in global media and in popular culture to describe a signals intelligence (SIGINT) collection and analysis network operated on behalf of the five signatory states to the UK–USA Security Agreement (Australia, Canada, New Zealand, the United Kingdom, and the United States,...
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  Global Positioning System

  The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites. It is maintained by the United States government...
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  Galileo spacecraft

  Galileo was an unmanned NASA spacecraft which studied the planet Jupiter and its moons. Named after the Renaissance astronomer Galileo Galilei, it was launched on October 18, 1989, by the Space Shuttle Atlantis on the STS-34 mission. Galileo arrived at Jupiter on December 7, 1995, via gravitational...
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  High-definition television

  High-definition television (HDTV) provides a resolution that is substantially higher than that of standard-definition television. HDTV may be transmitted in various varieties: The letter "p" here stands for progressive scan while "i" indicates interlaced. When transmitted at two megapixels per...
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  Hydropower

  Hydropower or water power is power derived from the energy of falling water, which may be harnessed for useful purposes. Since ancient times, hydropower has been used for irrigation and the operation of various mechanical devices, such as watermills, sawmills, textile mills, dock cranes, and...
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  International Space Station

  The International Space Station (ISS) is a habitable artificial satellite in low Earth orbit. It follows the Salyut, Almaz, Skylab and Mir stations as the ninth space station to be inhabited. The ISS is a modular structure whose first component was launched in 1998. Like many artificial satellites,...
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  Standard-definition television

  Standard-definition television (SDTV) is a television system that uses a resolution that is not considered to be either enhanced-definition television (EDTV) or high-definition television (HDTV). The term is usually used in reference to digital television, in particular when broadcasting at the...
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  SETI

  The search for extraterrestrial intelligence (SETI) is the collective name for a number of activities people undertake to search for intelligent extraterrestrial life. Some of the most well known projects are run by Harvard University, the University of California, Berkeley and the SETI Institute....
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  SIGINT

  Signals intelligence (often contracted to SIGINT) is intelligence-gathering by interception of signals, whether between people ("communications intelligence"—COMINT), whether involving electronic signals not directly used in communication ("electronic intelligence"—ELINT), or combinations of the...