The four global navigation satellite systems that power everything from your phone's map to precision agriculture and military operations — compared head-to-head on accuracy, coverage, satellites, frequencies and orbits.
Last updated: · · Sources: GPS.gov, ESA, IAC, BeiDou.gov.cn
Four fully operational Global Navigation Satellite Systems (GNSS) provide positioning, navigation, and timing (PNT) services worldwide. The US Global Positioning System (GPS) was first, reaching full operational capability in 1995. Russia's GLONASS, Europe's Galileo, and China's BeiDou have since achieved global coverage, giving users unprecedented redundancy and accuracy.
Modern receivers in smartphones and vehicles typically use signals from all four constellations simultaneously, providing sub-metre accuracy in good conditions. This multi-constellation approach is critical for applications like aviation, autonomous vehicles, precision agriculture, and financial transaction timing.
Two regional systems supplement the global four: Japan's QZSS (Quasi-Zenith Satellite System) enhances GPS coverage over the Asia-Pacific region, and India's NavIC (formerly IRNSS) provides regional coverage over India and surrounding areas.
| Parameter | GPS (US) | GLONASS (Russia) | Galileo (EU) | BeiDou (China) |
|---|---|---|---|---|
| Operator | US Space Force | Roscosmos / VKS | European Union / ESA | China (CNSA / PLA) |
| Full operational capability | 1995 | 1995 / restored 2011 | 2024 (FOC declared) | 2020 (BDS-3) |
| Design constellation | 24 satellites (6 planes) | 24 satellites (3 planes) | 30 satellites (3 planes) | 35 satellites (3 orbits) |
| Active satellites (2026) | ~31 | ~24 | ~30 | ~45 |
| Orbit altitude | 20,180 km (MEO) | 19,130 km (MEO) | 23,222 km (MEO) | MEO + GEO + IGSO |
| Orbital period | 11h 58m | 11h 15m | 14h 7m | 12h 53m (MEO) |
| Orbital inclination | 55° | 64.8° | 56° | 55° (MEO) |
| Civilian accuracy | ~1.0 m (L1/L5) | ~2.0 m | ~0.2 m (HAS) | ~1.0 m (public) |
| Signal access | Free (civilian) | Free | Free (OS) / encrypted (PRS) | Free (public) / restricted |
| Primary frequencies | L1, L2, L5 | L1, L2, L3 | E1, E5a, E5b, E6 | B1I, B1C, B2a, B3I |
Accuracy: Galileo's High Accuracy Service (HAS) delivers 20 cm-level positioning for free — the most accurate civilian GNSS service. GPS provides approximately 1 metre accuracy with dual-frequency receivers. GLONASS is slightly less accurate but offers excellent high-latitude coverage due to its 64.8° orbital inclination.
Architecture: BeiDou is unique in using a hybrid constellation with MEO, GEO, and inclined geosynchronous (IGSO) satellites, providing enhanced regional accuracy over China and the Asia-Pacific. The other three systems use only MEO satellites.
Independence: Each system was built to provide sovereign positioning capability independent of foreign control. This redundancy means that even if one system were degraded or denied, multi-constellation receivers would continue to function using the remaining systems.
Interoperability: All four systems are designed to be interoperable, with overlapping frequency bands enabling multi-GNSS receivers to combine signals for improved accuracy, availability, and integrity. The ICG (International Committee on GNSS) coordinates compatibility standards.