The Asia-Europe International Time Comparison Based on Beidou Achieved First

Recently, the National Time Service Center (NTSC), Chinese Academy of Sciences (CAS) achieved international time comparison based on the 7000km-long baseline of Beidou Navigation Satellite System (BDS), this was the first case internationally and it is of great value and importance for BDS application to go global.

Based on China’s UTC (NTSC), the Laboratory of Time and Frequency Primary Standards of NTSC conducted this long-distance international time comparison by using Beidou common view method and through the contrast test with Swedish UTC, which is maintained by Research Institutes of Sweden (RI.SE). With the precision of 2.25 nanoseconds, the test also has long-distance performance indicators that are as precise as the GPS common view of the U.S in the situation where Beidou is not completed yet (can only observe 4 satellites in Europe). The international time comparison between Asia and Europe has technically prepared Beidou for its inclusion of TAI reduction links, which is significant for the international use of Beidou system.

          It is reported that in addition to RI.SE, the Laboratory of Time and Frequency Primary Standards has entered into cooperation on Beidou international time comparison with world major research institutions on time frequency like Real Observatorio de la Armada (ROA), Physikalisch Technische Bundesanstalt (PTB), Russian Metrological Institute of Technical Physics and Radio Engineering (VNIIFTRI) and ChungHwa.