The Sun is approaching the peak of its 11th activity cycle, Solar Cycle 25. This means more geomagnetic storms and mysterious "plasma bubbles" at the equator, known as Equatorial Plasma Bubbles. These phenomena create ionospheric scintillations: the satellite signal trembles like starlight on the horizon. For your smartphone, it is a nuisance; for a drone or a self-driving car, it can become a serious problem.
A research team put precision navigation, called Precise Point Positioning (PPP), to the test using over twenty months of data from stations scattered globally, mostly in the equatorial belt. They compared GPS-only performance with the GPS + Galileo combination, the European system. Data comes from the European Space Agency (ESA) final products and the MGEX network.
The verdict is clear. On "calm" days, precision is at the centimeter level. When the ionosphere shakes violently, positioning errors with GPS alone more than double. The culprit is "cycle slips": the receiver momentarily loses track of the radio wave phase, like stumbling in the dark.
The good news: integrating Galileo changes the game. More satellites in view, different frequencies, and better geometry allow the system to "hold firm" even when the sky is turbulent. It is like walking a tightrope: having two safety ropes (GPS and Galileo) is worth much more than one.
This research, published in *Remote Sensing*, reminds us that space is not empty: it is a dynamic environment we must learn to understand to navigate safely, on Earth and beyond.
