GPS
The Global Positioning System (GPS), originally Navstar GPS,[2] is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force.[3]
The GPS service is controlled by the United States government, which can selectively deny access to the system, as happened to the Indian military in 1999 during the Kargil War, or degrade the service at any time.[9] As a result, several countries have developed or are in the process of setting up other global or regional satellite navigation systems. The Russian Global Navigation Satellite System (GLONASS) was developed contemporaneously with GPS, but suffered from incomplete coverage of the globe until the mid-2000s.[10] GLONASS can be added to GPS devices, making more satellites available and enabling positions to be fixed more quickly and accurately, to within two meters (6.6 ft).[11] China's BeiDou Navigation Satellite System began global services in 2018, and finished its full deployment in 2020.[12] There are also the European Union Galileo positioning system, and India's NavIC. Japan's Quasi-Zenith Satellite System (QZSS) is a GPS satellite-based augmentation system to enhance GPS's accuracy in Asia-Oceania, with satellite navigation independent of GPS scheduled for 2023.[13]
https://en.wikipedia.org/wiki/Global_Positioning_System