Fig. 1. Schematic diagram of two-way time comparison between satellite and ground

Fig. 2. Conveyor belt synchronization principle

Fig. 3. Schematic diagram of clock offset measurement scheme

Fig. 4. Clock synchronization scheme

Fig. 5. Relationship among clock offset measurement accuracy, speed of delay device, and bandwidth of entangled photon pair. (a) Three dimensional drawing; (b) projection drawing

Fig. 6. Relationship between measurement time and signal-to-noise ratio