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How does GPS work

Facts for Prelims (FFP)


Source: TH


Context: The article discusses the functionality and significance of the Global Positioning System (GPS).

  • Established by the U.S. Department of Défense in 1973, GPS is a constellation of 24 satellites orbiting the Earth, providing location information through a network of ground control stations and user devices.



  • The GPS system consists of three main segments: the space segment with 24 satellites in six orbits, the control segment managing satellite performance and commands, and the user segment incorporating GPS across various sectors like agriculture, construction, military operations, and more.
  • The satellites emit radio signals at specific frequencies (L1 and L2) with encoded information about their location and time.
  • GPS receivers on devices, like smartphones, pick up these signals to calculate the distance from satellites and, by triangulation, determine the user’s precise location in three dimensions of space and one of time.

Other Global Navigation Satellite Systems (GNSS) worldwide, such as GLONASS, Galileo, and BeiDou, operate alongside GPS.


India’s has developed NavIC system, comprising seven satellites with rubidium atomic clocks, and the GPS-Aided Geo Augmented Navigation (GAGAN) system, developed for civil aviation applications.