Satelliittipaikanmääritysjärjestelmä

Satelliittipaikanmääritysjärjestelmä, often referred to by its acronym GNSS (Global Navigation Satellite System), is a network of satellites that provides autonomous geospatial positioning with global coverage. These systems enable electronic receivers to determine their location, velocity, and time anywhere on or near the Earth. The most well-known GNSS is the United States' Global Positioning System (GPS), but other major systems include Russia's GLONASS, Europe's Galileo, and China's BeiDou.

The principle of operation relies on trilateration. A GNSS receiver on Earth listens for signals from multiple satellites. Each signal contains information about the satellite's position and the precise time the signal was transmitted. By measuring the time it takes for the signals from at least four satellites to arrive, the receiver can calculate its distance from each of those satellites. Knowing these distances and the satellites' positions in space, the receiver can pinpoint its own three-dimensional coordinates (latitude, longitude, and altitude) and synchronize its internal clock with atomic time.

GNSS technology has a wide range of applications. It is essential for navigation in vehicles, aircraft, and ships, as well as for personal navigation devices like smartphones. Surveying, mapping, precision agriculture, disaster management, and scientific research all rely heavily on accurate satellite positioning. The continuous development of GNSS aims to improve accuracy, reliability, and availability in all conditions, including urban canyons and areas with limited sky visibility.