Galileo HAS vs RTK: Can a Free Satellite Service Replace Precise Positioning

Precision farming relies on one simple principle: a tractor needs to know its position in the field within a few centimeters, not meters. In recent years, RTK systems have been the main way to achieve this. But in spring 2026, news emerged that made many agricultural producers reconsider whether a ground-based RTK network is even necessary if centimeter-level accuracy can come directly from a satellite.

What Real Field Tests of Galileo HAS Showed

On May 21, 2026, the European Union Agency for the Space Programme (EUSPA), together with Hemisphere GNSS and Case New Holland, tested the Galileo High Accuracy Service (HAS) under real field conditions. A tractor operated in automatic mode, and the results were compared against a reference RTK system.

The numbers turned out to be fairly convincing:

• horizontal error stayed consistently within 3-6 cm;
• 95% of horizontal error values stayed below 5.9 cm;
• maximum horizontal error remained under 8 cm;
• 95% of vertical error stayed within 12.4 cm;
• pass-to-pass accuracy (deviation between neighboring passes) reached 1.18 cm.

The main difference from the usual setup is that Galileo HAS corrections are broadcast directly via the Galileo E6 satellite signal, without connecting to a ground-based RTK network or an NTRIP server. In theory, this means a tractor could get centimeter-level accuracy almost anywhere within coverage, without a nearby base station.

How RTK, NTRIP, PPP, and Galileo HAS Differ

To understand where the new technology fits, it helps to briefly look at how the existing solutions actually work.

Is Galileo HAS Ready to Replace RTK Already

Here it's worth being cautious about drawing conclusions. EUSPA itself, in its own announcement, emphasizes the service's potential rather than claiming it's fully ready to replace RTK. Vertical accuracy and long-term stability of the results still need further testing across different conditions, crops, and seasons.

For operations where horizontal accuracy matters most, such as seeding or inter-row cultivation, the results look promising. But for tasks sensitive to vertical accuracy, like field leveling or drainage work, RTK remains the more reliable option for now. The stability of the Galileo E6 signal under heavy cloud cover, terrain obstructions, or crop canopy shielding is also still an open question, something that matters less for RTK thanks to its local base station.

The realistic scenario for the coming years is most likely not RTK being displaced, but the two technologies coexisting. Farms with their own base station and reliable equipment will continue getting proven centimeter-level accuracy without depending on satellite signal coverage, while Galileo HAS could become an additional or backup correction source where building dedicated infrastructure isn't economically justified.

Conclusion

The May 2026 Galileo HAS tests produced numbers that would have seemed unattainable for a free satellite service just a year earlier: 3-6 cm of horizontal accuracy with no ground infrastructure. That's a significant signal for the precision farming market, but not yet a reason to abandon proven RTK navigation. Over the coming years, both technologies will likely operate side by side, each covering the areas where it performs best.