Definition
GLONASS is the satellite-based radio navigation system operated by Russia, providing worldwide position, velocity, and time information to suitably equipped receivers. It performs the same basic function as the United States' GPS and operates as an independent constellation of satellites in medium Earth orbit. Many modern multi-constellation receivers use signals from both GPS and GLONASS satellites simultaneously to improve position accuracy and signal availability.
Plain English
GLONASS is Russia's version of GPS. It is a separate group of satellites that tells a receiver where it is, how fast it is moving, and the exact time. Some aviation and consumer receivers use it alongside GPS to get a better, more reliable position fix.
Context Anchor
Seen in GPS and satellite navigation discussions, especially when comparing the satellite systems an aircraft receiver may be able to use.
Derivation
GLONASS is a transliteration of the Russian name 'Globalnaya Navigazionnaya Sputnikovaya Sistema,' which translates directly as 'Global Navigation Satellite System.' Knowing the name simply means 'global satellite navigation system' makes clear it is a peer of GPS, not a subsystem of it.
Why Pilots Care
It supplies an independent source of satellite navigation data that improves position accuracy and provides backup when GPS signals are unavailable or degraded.
Intuition Check
GLONASS is not a GPS procedure or a GPS signal. It is a separate satellite navigation system that some receivers can use in addition to GPS.
Example Sentence 1
The portable tablet receiver picked up both GPS and GLONASS satellites, giving a faster position fix on the ramp.
Example Sentence 2
With both GPS and GLONASS enabled, the navigation display showed a tighter position solution than GPS alone.