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, Orbital Radar TLE data
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. As of March 2026, there are approximately 130 active GNSS satellites in orbit across the four systems.
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. See the regional systems section for details.
| 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) | 21,528 km 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) / encrypted (M-code) | Free (civilian) | Free (OS) / encrypted (PRS) | Free (public) / restricted |
| Primary frequencies | L1, L2, L5 | L1, L2, L3 | E1, E5a, E5b, E6 | B1I, B1C, B2a, B3I |
| Signal type | CDMA | FDMA + CDMA (K2+) | CDMA | CDMA |
| Reference frame | WGS 84 | PZ-90.11 | GTRF (ITRF-aligned) | CGCS2000 |
| Time reference | GPS Time (UTC-USNO) | GLONASS Time (UTC-SU) | Galileo System Time | BeiDou Time (BDT) |
Satellite counts verified from the Orbital Radar TLE catalog, which tracks 18,000+ objects. Counts include operational satellites only.
Galileo's High Accuracy Service (HAS), operational since 2024, delivers 20 cm-level horizontal accuracy for free — the most precise civilian GNSS service available. GPS follows at approximately 1 metre with dual-frequency receivers, while BeiDou matches GPS globally and exceeds it over the Asia-Pacific thanks to its GEO and IGSO satellites.
★ Galileo HAS is the most accurate free civilian positioning service. Bar widths represent relative error (smaller = more accurate). Real-world accuracy depends on receiver quality, environment, and satellite geometry.
| Scenario | Best primary system | Why |
|---|---|---|
| Urban driving / city navigation | Multi-GNSS (all four) | More satellites visible between buildings; better geometry reduces multipath errors |
| Open sky / surveying | Galileo HAS | 20 cm accuracy without paid correction services; best single-system precision |
| High latitudes (>55°N) | GLONASS + GPS | GLONASS's 64.8° inclination provides superior visibility in polar and sub-polar regions |
| Asia-Pacific region | BeiDou + QZSS | BeiDou's GEO/IGSO satellites enhance regional accuracy; QZSS augments GPS over Japan |
| Aviation (ICAO-certified) | GPS (primary) + Galileo | GPS has the longest aviation certification history; Galileo dual-frequency approved by EASA |
| Precision agriculture (RTK) | Multi-GNSS + RTK corrections | Maximum satellite count improves fix reliability; RTK provides centimetre accuracy |
| Financial timing (PNT) | GPS + Galileo | Both provide nanosecond-level UTC-traceable timing for stock exchanges and telecom |
| Military / sovereign | Own national system | Each nation uses encrypted military signals independent of foreign control |
Each GNSS transmits on multiple frequency bands to enable ionospheric error correction (dual-frequency) and serve different user communities. Modern multi-GNSS chipsets from Qualcomm, Broadcom, and MediaTek support most civilian signals from all four systems.
| System | Band | Signal | Freq. (MHz) | Access | Primary use |
|---|---|---|---|---|---|
| GPS | L1 | C/A, L1C, P(Y), M | 1575.42 | Civ / Mil | Primary civilian positioning; legacy receivers |
| L2 | L2C, P(Y), M | 1227.60 | Civ / Mil | Dual-frequency correction; surveying | |
| L5 | L5 | 1176.45 | Civilian | Safety-of-life (aviation); high-precision | |
| GLONASS | L1 | L1OF, L1OC | ~1602 (FDMA) | Civilian | Standard positioning |
| L2 | L2OF, L2OC | ~1246 (FDMA) | Civilian | Dual-frequency correction | |
| L3 | L3OC | 1202.025 | Civilian | CDMA signals on Glonass-K2 satellites | |
| Galileo | E1 | E1-OS, E1-PRS | 1575.42 | Open / PRS | Open service; interoperable with GPS L1 |
| E5a | E5a-OS | 1176.45 | Open | Dual-frequency; interoperable with GPS L5 | |
| E5b | E5b-OS | 1207.14 | Open | Safety-of-life; integrity data | |
| E6 | E6-HAS, E6-PRS | 1278.75 | HAS / PRS | High Accuracy Service (20 cm) | |
| BeiDou | B1I | B1I | 1561.098 | Open | Legacy open service (BDS-2) |
| B1C | B1C | 1575.42 | Open | New open service; interoperable with GPS L1 / Galileo E1 | |
| B2a | B2a | 1176.45 | Open | Dual-frequency; interoperable with GPS L5 / Galileo E5a | |
| B3I | B3I | 1268.52 | Open / Auth | Wide-area augmentation and authorised service |
Accuracy: Galileo's HAS delivers 20 cm-level positioning for free — the most accurate civilian GNSS. GPS follows at ~1 m with dual-frequency receivers. GLONASS is slightly less accurate (~2 m) but offers excellent high-latitude coverage due to its 64.8° inclination. BeiDou matches GPS globally and exceeds it over the Asia-Pacific.
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. BeiDou's GEO component also enables a regional short message service (RDSS) unique among GNSS.
Signal structure: GLONASS is the only system still using FDMA (frequency-division multiple access) on legacy signals, where each satellite transmits on a slightly different frequency. GPS, Galileo, and BeiDou all use CDMA. GLONASS is transitioning to CDMA with Glonass-K2 satellites, simplifying multi-GNSS receiver design.
Independence: Each system provides sovereign positioning capability independent of foreign control. Even if one system were degraded, multi-constellation receivers continue functioning using the remaining systems. This is critical for national security, critical infrastructure, and space situational awareness.
Interoperability: All four systems are designed to be interoperable, with overlapping frequency bands enabling multi-GNSS receivers to combine signals. A modern receiver has access to 130+ satellites — dramatically improving performance in challenging environments like urban canyons and dense forests.
Two regional satellite navigation systems supplement the four global constellations. While they don't provide worldwide coverage, they significantly enhance positioning accuracy within their service areas and are increasingly supported by consumer chipsets.
| Parameter | QZSS (Japan) | NavIC (India) |
|---|---|---|
| Operator | Cabinet Office of Japan | ISRO |
| Service area | Asia-Pacific (centred on Japan) | India + 1,500 km beyond borders |
| Constellation | 4 satellites (expanding to 7) | 7 satellites (3 GEO + 4 IGSO) |
| Orbit types | Quasi-zenith (HEO) + GEO | GEO + IGSO |
| Civilian accuracy | ~1 m / ~10 cm (CLAS) | ~5 m / ~1 m (restricted) |
| Augments | GPS (L1/L2/L5 compatible) | Independent + GPS L5 compatible |
| Key application | Centimetre positioning for autonomous vehicles and agriculture in Japan | Sovereign PNT for Indian defence, transport, and disaster management |
Multi-GNSS support has become standard across most consumer and professional devices. Here's what each category typically supports as of 2026:
| Device type | GPS | GLO | GAL | BDS | Notes |
|---|---|---|---|---|---|
| Smartphones (2020+) | ✓ | ✓ | ✓ | ✓ | Qualcomm, MediaTek, Apple all support four systems. Dual-frequency (L1+L5) common since 2022. |
| Car navigation (new) | ✓ | ✓ | ✓ | Varies | Most new vehicles support GPS + GLONASS + Galileo. BeiDou depends on chipset and market. |
| Aviation (ICAO) | ✓ | ✓ | ✓ | — | GPS primary. Galileo dual-frequency approved by EASA. BeiDou not yet ICAO-certified. |
| Precision agriculture | ✓ | ✓ | ✓ | ✓ | All four used for reliable RTK fix. Trimble, John Deere, Leica support multi-GNSS. |
| Wearables / fitness | ✓ | ✓ | ✓ | ✓ | Garmin, Apple Watch, Coros support multi-band GNSS. Dual-frequency in premium models. |
| Marine / offshore | ✓ | ✓ | ✓ | ✓ | IMO mandates GPS. Multi-GNSS provides critical redundancy for open-ocean navigation. |
| Timing / telecom | ✓ | — | ✓ | — | GPS and Galileo provide nanosecond UTC-traceable timing for exchanges and telecom. |
| Military | Own | Own | Own | Own | Each nation uses its own encrypted military signals for sovereign positioning. |
Galileo's High Accuracy Service (HAS) provides approximately 20 cm accuracy for free, making it the most accurate civilian GNSS service. However, modern multi-constellation receivers combine signals from all four systems for sub-metre accuracy that exceeds any single system alone.
Most smartphones manufactured since 2020 support all four GNSS systems. Your phone automatically selects the best combination of satellites from GPS, GLONASS, Galileo, and BeiDou to maximise positioning accuracy and reliability.
As of March 2026, there are approximately 31 active GPS (NAVSTAR) satellites in orbit across 6 orbital planes at 20,180 km altitude. The constellation was designed for 24 satellites, but extra satellites provide improved coverage and redundancy. Track the live GPS constellation →
GPS is one specific system operated by the US Space Force. GNSS (Global Navigation Satellite System) is the umbrella term for all satellite navigation systems: GPS (US), GLONASS (Russia), Galileo (EU), and BeiDou (China). Modern devices use multi-GNSS receivers that combine signals from all four for the best accuracy.
Yes. Galileo provides global coverage and its Open Service signals are free to use anywhere in the world, including the US. Most modern smartphones and GNSS receivers sold in the US already support Galileo alongside GPS.
GLONASS has the highest orbital inclination (64.8°) of any GNSS, giving it superior satellite visibility at latitudes above 55°N. This makes GLONASS particularly valuable in Scandinavia, Russia, Canada, and Alaska where GPS geometry alone can be weaker.
Solar storms cause ionospheric disturbances that can degrade positioning accuracy by several metres. In severe events, signals can be disrupted entirely. Dual-frequency receivers mitigate this by measuring the ionospheric delay directly. Learn more →