GLONASS (Russian System) - GLObal NAvigation Satellite System is a space-based satellite navigation system operated by the Russian Aerospace Defense Forces. It provides an alternative to Global Positioning System (GPS) and is the second alternative navigational system in operation with global coverage and comparable precision.

Now a days, manufacturers of GPS devices say that GLONASS system increased the number of satellites available to them. It means that the global positions can be fixed more quickly and accurately, especially in built-up areas where the view to some GPS satellites is obscured by buildings. From 2015 ahead, Glonass is being also used in addition of GPS System in most modern smartphones as iPhone and Samsung models. It happened also to most modern Drones and Quadcopters. The new generation of Drones are able to capture both signals, one from GPS System (EUA) and another from GLONASS (Soviet Union). GLONASS has a fully operational constellation of 24 Satellites with global coverage located in middle circular orbit at 19.100 km altitude with a 64.8 degree inclination and a period of 11 hours and 15 minutes. GLONASS' orbit makes it especially suited for usage in high latitudes (north or south), where getting a GPS signal can be problematic. At peak efficiency, the standard-precision signal offers horizontal positioning accuracy within 5 to 10 meters, vertical positioning within 15 meters. To get a position fix the Glonass receiver must be in the range of at least four satellites. Actually, only the United States Global Positioning System (GPS) and the Russian GLONASS have global operational GNSS systems. China is in the process of expanding its regional BeiDou Navigation Satellite System into the global navigation system till 2020. The European Union's Galileo (satellite navigation) is a GNSS in initial deployment phase, scheduled to be fully operational by 2020 at the earliest. France, India and Japan are in the process of developing other navigation systems.