A direct comparison between two independently calibrated time transfer techniques: T2L2 and GPS common-views

This paper presents a direct comparison of two time transfer techniques on independently calibrated links: Time Transfer by Laser Link (T2L2) and Global Positioning System (GPS) satellite common-views (CV). The two different techniques are described, along with the independent link calibrations. The results achieved during one measurement campaign involving three European laboratories are presented, the differences between the two techniques remaining in average below 300 ps, with a standard-deviation below 500 ps mostly due to GPS CV.