The GIOVE-A satellite offers the first chance to evaluate the performance of Galileo signals in real-life situations, under interference and multi-path. The satellite sent its first signals on January 12, 2006. During the same time, payload commissioning, in-orbit tests, and frequency filing were carried out and concluded on February 20 and March 9, 2006, respectively. The Galileo signal experimentation represents the fourth GIOVE-A objective. Under this objective, experimentation and characterization of user environments and related receiver performances, and sensor-station environment and measure performance were carried out. The first activity is designed to show the feasibility of obtaining and tracing Galileo signal using a real representative signal-in-space, as well as to verify the anticipated performance in real-life conditions. The focus of this activity is to compare the various modulations in a small number of diverse conditions for both static and kinematic applications and then rank them according to performance. The second activity aims to evaluate sensor-station receiver measurement performance focusing on actual Galileo signals deployed worldwide. The code and carrier phase measurements are vital to orbit determination, time synchronization, and integrity determination. The focus of this activity is to obtain statistically significant performance calculations for several sensor-stations measurement performances, as well as to compare the various stations. Experimentations done on signal, receiver, and sensor-stations showed that the performance of all Galileo signals is much better than GPS-C/A with respect to nose and multipath performance.