Global Navigation Satellite System

Why Trust Techopedia

What Does Global Navigation Satellite System Mean?

A global navigation satellite system (GNSS) is a type of satellite navigation that provides global coverage. A GNSS is defined by a constellation of orbiting satellites working together with a network of ground control stations and receivers that calculate ground positions through an adapted version of trilateration.


To date, there are only two operational GNSSs, the United States’ NAVSTAR Global Positioning System (GPS) and the Russian Federation’s Global Navigation Satellite System (GLONASS). However there are two other satellites undergoing development, the European Union’s Galileo and China’s Compass or BeiDou-2.

Techopedia Explains Global Navigation Satellite System

A global navigation satellite system is a constellation of satellites that provide geo-spatial positioning to many devices autonomously, allowing electronic devices with the appropriate receivers to determine their precise location on the surface of the Earth.

The initial motivation for a satellite system was for military applications, but it has now progressed to more extensive civil applications, including the following:

  • Aviation
  • Disaster warning and emergency response
  • Land transportation
  • Maritime
  • Mapping and surveying
  • Monitoring of the environment
  • Precision agriculture
  • Natural resources management
  • Research, such as climate change and ionospheric studies
  • Wireless networking
  • Photographic geocoding
  • Mobile satellite communications
  • Precise time reference
  • Military precision-guided munitions

Generally the global coverage can be achieved through a satellite constellation of 20 to 30 medium Earth orbit (MEO) satellites. Each satellite would be placed between several orbital planes. Current systems vary, but altogether set the orbital inclinations to > 50° and their orbital periods to roughly 12 hours at an altitude of almost 12,000 miles (20,000 km).


Related Terms

Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.