Four global navigation satellite systems are scheduled to be fully operational orbiting Earth in the coming years: the NAVSTAR Global Positioning System (GPS) from the United States, the GLObal NAvigation Satellite System (GLONASS) from Russia, the Compass/BeiDou-2 System (BDS) from China, and Galileo from Europe. A considerably high number of signals, coming from the satellites of those constellations, will share the radio electric spectrum.
By Inside GNSSIn February 2011, Russia launched the first satellite of the GLONASS-K1 series, i.e., SVN (space vehicle number) 801 (R26), which in addition to the legacy frequency division multiple access (FDMA) signals, for the first time was enabled to transmit code division multiple access (CDMA) signals on the GLONASS L3 frequency (1202.025 MHz). Later in 2014, the GLONASS program added SVNs 802 (R17) of series K1 and 755 (R21) of series M, and in 2016, SVN 751 of series M, with the capability of transmitting CDMA L3 signals to the constellation.
By Inside GNSSContemporary times have seen an increase in the number of navigation satellites across various geographical regions. In order to ensure that all these satellite systems work together to optimize the positioning, navigation, and timing (PNT) of users on or near the Earth’s surface there is need for inter-cooperation and inter-operability of the systems.
By Inside GNSSReturn to main article: "Inter-Signal Correction Sensitivity Analysis"
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By Inside GNSSReturn to main article: “GNSS Evolutions for Maritime”
By Inside GNSSReturn to main article: “GNSS Evolutions for Maritime”
By Inside GNSS