Stability of Hardware Delays of GNSS Signals

The goal of this study is to analyse the stability of the hardware delays of GPS and Galileo signals in multi-GNSS stations dedicated to time transfer. We first demonstrate a significant sensitivity of these delays to external environment (multipath, weather), up to 2 ns in case of snow when the antenna is not protected by a radome. Furthermore, we notice that the long-term stability of the Galileo E5a code and GPS C5 code measurements is poorer than for the other code measurements.