Laser time transfer and its application in the Galileo programme

Combining the laser pulse emission times, propagation delays and satellite arrival times the ground to space clock comparison may be accomplished. The timing precision of the order of 1 × 10−12 s and a time transfer accuracy of 50 ps is achievable. This precision and accuracy is at least one order of magnitude better in the optical region than in the radio frequency wavelength region. All the components of the proposed instruments are available in Europe, the ground segment of the proposed project is existing, the measurement techniques and data flow and processing procedures are well established. The implementation of new picosecond timing technologies and the laser time transfer into the Galileo programme will improve the precision and accuracy of the satellite on-board time scale and position prediction with unprecedent precision and accuracy. Both these facts will contribute to the Galileo system overall accuracy and performance and simultaneously will enable new experiments in fundamental physics.