7 EUROPEAN, RUSSIAN, AND OTHER SATELLITE SYSTEMS

Beginning in 1982, the Soviet Union deployed a satellite positioning system, which bore many similarities to GPS. GLONASS—a Russian acronym for Global National Satellite System—uses atomic clocks onboard and frequencies in the L-Band. Like GPS, GLONASS receivers determine position based on the time of arrival of the signals from the satellites. Like GPS, it was open to qualified civilian users. And even before the breakup of the Soviet Union, in 1989, the USSR agreed to make it interoperable with GPS.
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