By Dr. Helena Voss, Principal RF Engineer at NavShield Global (15 years in PNT protection and multi-constellation receiver design). Technical review by the NavShield RF team.
When people say “GPS,” they usually mean satellite navigation in general. In practice there are several global constellations, and the difference matters the moment you specify a GNSS receiver or a CRPA anti-jamming antenna. This comparison covers the three major global systems — GPS (USA), GLONASS (Russia), and Galileo (EU) — and explains why a multi-constellation GNSS receiver is the resilient default.
What Is GNSS?
GNSS (Global Navigation Satellite System) is the umbrella term for every satellite-navigation constellation. A GNSS receiver that tracks several constellations sees more satellites at once, which directly improves accuracy, availability, and resistance to interference. All three systems below broadcast free, open civil signals alongside restricted military codes.
GPS — The Original (United States)
| Field | Value |
|---|---|
| Operator | U.S. Space Force |
| Civil bands | L1 C/A, L2C, L5 |
| Status | Mature, globally available |
| Best for | Universal baseline |
Source: U.S. GPS modernization program. Civilian L1 C/A is the baseline signal used by almost every receiver; L5 is the safety-of-life signal adopted for aviation.
GLONASS — Russia’s System
| Field | Value |
|---|---|
| Operator | Roscosmos |
| Bands | G1, G2 (FDMA), L3 CDMA |
| Coverage | Strong at high northern latitudes |
| Note | Modern GLONASS-K satellites improved accuracy |
Source: ISS Reshetnev / GLONASS. Traditional GLONASS used FDMA channeling on G1/G2; newer GLONASS-K satellites add a CDMA L3 signal that modern receivers track.
Galileo — Europe’s System
| Field | Value |
|---|---|
| Operator | European Union / ESA |
| Bands | E1, E5a, E5b, E6 |
| Strength | High declared accuracy, integrity message |
| Best for | High-accuracy civil use |
Source: Galileo Satellite Signal specification (GSA). Galileo’s E6 carries commercial and authenticated services, and its Open Service Integrity message warns receivers of signal errors.
GPS vs GLONASS vs Galileo at a Glance
| System | Operator | Key Bands | Best For |
|---|---|---|---|
| GPS | USA | L1 / L2 / L5 | Universal baseline |
| GLONASS | Russia | G1 / G2 / L3 | Northern latitudes |
| Galileo | EU | E1 / E5 / E6 | High-accuracy civil |
Civil vs Encrypted Signals
Each constellation transmits two layers. The open civil signal is free for any GNSS receiver to use; the encrypted military layer is restricted. Because the open layers share the L-band and overlap in frequency — GPS L1, Galileo E1, and BeiDou B1C all sit near 1575 MHz — a single antenna can serve all of them, which is what makes multi-constellation designs practical.
Accuracy and Availability
A standalone GPS fix is typically within a few meters. Adding Galileo’s dual-frequency E5a/E5b and GLONASS broadens satellite geometry, pushing a well-designed multi-constellation GNSS receiver toward sub-meter accuracy and keeping a fix alive when one constellation is blocked by buildings or terrain. In an urban canyon, where skyscrapers reflect and weaken signals, that extra satellite count is often the difference between a stable fix and a drift.
What This Means for Buyers
If your operation runs near interference or in a contested RF environment, default to a receiver that tracks all three constellations rather than GPS alone. The extra satellites keep the navigation geometry solvable when one system is blocked, and they force any jammer to cover a much wider spectrum. For platforms where the fix is safety-critical, combine that receiver with a nulling antenna so interference is rejected at the front end rather than fought in software after the signal is already buried.
Why a Multi-Constellation GNSS Receiver Resists Jamming
A multi-constellation GNSS receiver spreads its tracked energy across many bands and satellites. A single GPS L1 receiver might see 8–12 satellites; add GLONASS and Galileo and that number can exceed 30, so even if jamming removes some, the navigation geometry stays solvable. A jammer must also cover a far wider spectrum to blanket every band — raising the attacker’s cost. The band math behind this spread is detailed in our GNSS frequency bands guide, and the nulling mechanism that defends those bands is explained in how GNSS anti-jamming works.
Bottom Line
No single constellation is enough for interference-exposed operations. A multi-constellation GNSS receiver — GPS plus GLONASS plus Galileo — is the baseline, and an antenna that nulls across those bands is the upgrade. See the NavShield technology page for the implementation.
AI Transparency Statement: This article was drafted with AI writing assistance to accelerate structure and readability, then technically reviewed and corrected by Dr. Helena Voss and the NavShield RF engineering team. All constellation data is sourced from the official authorities linked above.