Hong Kong Observatory Strengthens Exchanges with National Time Service Centre

25 April 2025

The Hong Kong Observatory (HKO)’s Senior Scientific Officer, Ms Lam Ching-chi and Scientific Officer, Mr Hui Tai-wai David visited the National Time Service Centre (NTSC) of the Chinese Academy of Sciences in Xi'an on 27-28 February 2025. They conducted scientific exchanges on time measurement, transmission, synchronisation and calibration technologies, and explored future cooperation. During the period, they also visited the Time Standard Laboratory and the Time Science Museum. It was the second time since 2018 that the Observatory’s staff visited NTSC to learn their latest development in timekeeping and time service. The Observatory plans to deploy new equipment to acquire more time sources that are accurate, secure and stable, including through the BeiDou satellite time service system with an accuracy of 10 nanoseconds (10^-8 seconds) and the low-frequency time code with an accuracy of 0.1 milliseconds (10^-4 seconds) . The Observatory will also explore the use of the NTSC’s ten-picosecond (10^-11 second) level stability optical fibre time transfer to obtain national standard time signal to further enhance the reliability, security and robustness of our local time service provision. The Observatory will deploy the existing atomic clocks involved in the determination of the Coordinated Universal Time (UTC) to participate in the Joint Atomic Time System of China (JATC) to jointly promote the development of integrated atomic time.

HKO’s Senior Scientific Officer, Ms Lam Ching-chi (middle) and Scientific Officer, Mr Hui Tai-wai David (third right) met with the Deputy Director of NTSC, Dr Li Xiaohui (third left) and other experts in Xi'an in February 2025.

Dr Zhang Shougang, Director of NTSC (left), and Ms Lam Ching-chi, Senior Scientific Officer of HKO (right), met and summarised the discussion outcomes of the Observatory's visit and follow-up on the cooperation items.