User demand and technical scheme of the " High Precision Ground-based Time Service System（GTSS）" seminar was held in Beijing on May 21, 2017. The meeting was organized by the National Time Service Center，Chinese Academy of Sciences（NTSC，CAS）, more than 80 experts from over 50 units including the military，research institutes，universities，enterprises and so on attended An expert from Time Department of Bureau International des Poids et Mesures（BIPM） was also present.
At the meeting, firstly, Zhang Shougang, the director of NTSC introduced the purpose of the meeting, Jin Duo, a researcher from the Institute of Physics, Chinese Academy of Sciences, expounded the process and management rules of national large research infrastructure. Li Xiaohui, the vice-director of NTSC, presented the construction scheme and current progress of the system. After that, experts discussed the reports and offered some positive advice about user demand, scientific objectives and application targets on the GTSS and then reached a consensus that GTSS as a national large research infrastructure platform would further enhance the safety, stability and timing precision of time service system of our country and has important sense to scientific research, nation security and basic industry. At last, considering the urging status of constructing, the relative mature technology support and excellent basic conditions, experts suggested that the GTSS should be applied and implemented as soon as possible.
The GTSS was on the priority list of 10 “13th Five-Year" national large research infrastructures. It mainly includes: adding enhanced long range navigation (e-LORAN) time service stations, realizing long wave timing signal’s nationwide cover and improving critical areas’ timing precision to a level less-than 100 nanosecond (ns); Taking advantage of Optical fiber time-frequency network to link the Communication Optical fiber network of major cities and key users with a time passing precision less-than 100 picosecond (ps) and a frequency passing precision at the magnitude of E- 19.
The seminar focused on GTSS’ wide users demand on time keeping, time-frequency passing, satellite navigation, basic physics research, astronomical experiment observation, geodesy and so on.
After constructed, GTSS will work together with the satellite-based time service system to facilitate the national integrated time service system which would be an important test platform for scientific research and related engineering technology, such as accurate physical measurement, precise time-frequency technique, and so on, and will play a key role in long-term development of our country and society.
GTSS user demand and technical scheme seminar (Image by NTSC)