GLONASS

GLONASS (Global Navigation Satellite System) is a global satellite navigation system independently developed and operated by Russia, recognised alongside the US's GPS, China's BeiDou (BDS), and the European Union's Galileo as one of the world's four core satellite navigation networks. The development of GLONASS commenced during the Soviet era, engineered to deliver all-weather, high-precision, real-time positioning, velocity, and timing reference services for land, sea, air, and space users globally. As one of the multi-constellation satellite positioning sources widely integrated into modern smartphones and in-car navigation systems, GLONASS offers distinct coverage and signal geometry advantages across high-latitude and polar regions.

Core Technical Architecture and Operating Principle

The technical architecture of GLONASS primarily comprises a space constellation, ground-based control and monitoring stations, and user receiver terminals: 

Multi-Orbital Constellation Layout and FDMA/CDMA Regime: 

The GLONASS constellation typically consists of dozens of operational satellites deployed across three Medium Earth Orbit (MEO) planes. Unlike GPS, which employs Code Division Multiple Access (CDMA) by broadcasting on identical carrier frequencies differentiated by unique pseudo-random noise codes, traditional GLONASS satellites utilise Frequency Division Multiple Access (FDMA) technology, where each satellite transmits on slightly different radio carrier frequencies to distinguish signals. In recent years, next-generation satellites such as the GLONASS-K series have progressively adopted CDMA signal structures to ensure compatibility with mainstream international standards.

3D Spatial Intersection Ranging and High-Latitude Geometric Resolution:

Receiver units (such as in-car navigation modules) calculate the precise distance between satellites and the vehicle by simultaneously receiving broadcast ephemeris and ranging signals from multiple GLONASS satellites to measure electromagnetic wave propagation delays. Combined with the satellites' precise orbital coordinates, the system utilises the spatial distance intersection principle (trilateration) to compute the vehicle's 3D latitude, longitude, altitude, and precise time synchronisation in the Earth coordinate system in real time with high accuracy. 

Safety Regulations and Physical Limitations

Prohibiting Blind Reliance on a Single Satellite Navigation System in Strong Electromagnetic Interference Zones, Beneath Dense Urban Flyovers, or in Deep Canyons: 

Although modern in-car systems generally feature multi-mode, multi-constellation (GPS + GLONASS + BeiDou + Galileo) integrated positioning, satellite navigation remains vulnerable to multipath effects, signal dropouts, or positioning drift under intense electromagnetic interference, severe weather, or heavily obstructed environments. Drivers must never engage in hazardous driving by blindly relying on navigation guidance when road conditions are not clearly visible; where necessary, dead reckoning (DR) correction combining wheel speed sensors and inertial sensors should be utilised. 

Prohibiting the Disregard of Risks Concerning Precision Fluctuations or Brief Signal Outages in Specific Satellite Navigation Systems Due to Geopolitics, Frequency Interference, or Space Weather Variations: 

Satellite navigation signals are inherently weak and susceptible to space weather phenomena (such as ionospheric scintillation caused by solar storms) as well as intentional radio spoofing and electronic jamming. During critical autonomous driving navigation tasks or operations demanding extreme timing accuracy, control errors caused by abrupt frequency interference or performance degradation of a single navigation system (such as GLONASS) are strictly unacceptable; intelligent driving systems must be equipped with multi-source sensor fusion perception and redundant fail-safe backup capabilities.