One-way time transfer using geostationary satellite TDF2

The way that geostationary television satellites can easily be used to perform common-view time transfer between remote clocks is presented. Different parameters and sources of error that have to be kept under control in order to achieve time transfer with a precision of 10 ns is reviewed. Two different methods are elaborated to eliminate the influence of satellite residual motion with a final precision that can reach 10 ns. Experimental results obtained on common-view time transfer measurements using the TV satellite TDF2 between four French laboratories show that frequency transfer can be performed with a stability of 1 part in 10¹⁴ for an averaging time of 10 days. The comparison of time transfer results with accurate common-view GPS data available between the four stations and with orbit data provided by the CNES showed measurement biases that are most likely due to errors in the antenna coordinates