Frequency transfer using GPS carrier phases: influence of temperature variations near receiver

Carrier phase data from geodetic GPS receivers, driven by atomic clocks, and belonging to the IGS network, have been used to demonstrate the capabilities of the GPS carrier phases for frequency transfer. Zero baseline tests with a common reference frequency show that-for averaging times of only 8 hours a frequency stability going from 4.10^-15 to 1.10^-16 can be reached, depending on the temperature variations to which the receiver hardware is subject. On a regional baseline, frequency stabilities (obtained for averaging durations of 4 hours) of 1.10^-14 are improved up to 2.10^-15, through a proper modeling of the tropospheric refraction and by keeping ambient temperature variations under control