Galileo-SDR-SIM: An Open-Source Tool for Generating Galileo Satellite Signals

Abstract

In today’s world, satellite navigation systems, like GPS, are crucial for many essential tasks, such as guiding self-driving cars and managing power grids and transportation. These systems depend on signals continuously transmitted by satellites in orbit, providing accurate location and timing information. Galileo is one of these satellite systems that is becoming increasingly important. It has recently added security features to ensure the information it sends is genuine, resulting in a growing demand for Galileo (ESA (2023)). They must be tested thoroughly to ensure Galileo-dependent applications work well and are secure. One challenge is that researchers and developers need a way to create custom Galileo signals for their tests. Commercial signal generators are available but expensive and may not be accessible to many researchers. That’s why there’s a need for an open-source Galileo Signal Generator that is highly accessible. This paper introduces “Galileo-SDR-SIM”, a tool for generating and transmitting Galileo signals. It connects easily to software-defined radios, making it possible to send these signals in real-time. We’ve tested it extensively with various GNSS receivers, including software-defined receivers (GNSS-SDR 2) and hardware receivers from well-known manufacturers like u-Blox 3 4. The results show that COTS receivers can obtain a 3D fix with a mean location offset of only 1.055 meters. Finally, we release our implementation as open source for further development^5.