Thales Avionics Tracks L1 Signal of First Galileo Satellite

Following the recent launch of two Galileo in-orbit validation satellites, Thales Avionics of Valence, France, has successfully acquired and tracked the new L1 Open Service signal transmitted by one of the space vehicles (PRN 11) on Monday, December 12, at 13:30 (GMT). Thales Avionics has developed a Galileo receiver capable of processing the Open Service, Commercial Service, and Safety of Life service of the Galileo constellation.

Figure 1 shows a screenshot of the receiver interface program highlighting the L1 signal energy (top right) and the pilot secondary code (bottom).

Figure 1: Real-time measurements.

The satellite Doppler and C/N₀ values have been recorded and are provided below.

The raw navigation message has been decoded. It contains INAV type 0 and INAV dummy data as shown in the next figure. These messages enable Galileo system time transfer.

The signal modulation and characteristics show no discrepancy relative to the Galileo Open Service ICD released last year.

The fact that only L1 frequency is broadcast for the moment prevents providsion of further  results based on dual-frequency measurements.

Thales has developed a coherent processing of the Galileo E5 AltBOC(15,10) signal compatible with hardware architecture designed for independent processing of both E5a and E5b. This processing is fully compatible with the mismatch between the two RF channels on E5a and E5b, thanks to real-time calibration based on satellite signals. This processing only requires software implementation, without additional recurrent costs. The technique is relevant for future receivers operating in the E5 band, in order to significantly enhance the accuracy, with respect to thermal noise and multi-path, and to improve the cycle slip probability.

Thales Avionics, involved for many years in GNSS receivers design and production, has developed a Galileo receiver capable of processing the Open Service, Commercial Service, and Safety of Life service of the Galileo constellation. This high-end receiver includes patented state of the art algorithms capable of processing up to four different frequencies.