In the 1960s, due to the demands of large-scale economic construction, China decided to build a special time service station in the hinterland of China as soon as possible. Pucheng, after investigation organized by the Chinese Academy of Sciences, was selected to establish the Northwest Time Service Station by experts from the Shanghai Observatory, Purple Mountain Observatory and Beijing Observatory.
In 1966, the station was started to construction. And in 1970, the short wave time service station was almost completed, named as Shaanxi Astronomy Observatory, whose work concentrated on the time service, and carried out the research of universal time, atomic time and astrometry. The Shaanxi Astronomy Observatory established an astronomical time determination system based on photoelectric transit instruments and photoelectric astrolabes, as well as an atomic time-frequency reference based on domestic rubidium atomic clocks and hydrogen atomic clocks. In the early 1980s, the BPL long wave time service system was set up, whose timing accuracy reached microsecond level. On this account, China's radio time service technology step into the advanced level of the world, and met the emergency requirement of national economic construction at that time.
In 1980, Shaanxi Astronomy Observatory's time-frequency reference and other laboratories, administrative department were moved to Lintong, Shaanxi province. In the 1980s and 1990s, The Shaanxi Astronomy Observatory upgraded their technologies in the long and short wave time service system and the atomic time reference, constructed the BPC low frequency time-code signal time service system, as well as series of new time service system such as telephone and network.; the BPC low frequency time-code signal time service system was constructed; network, telephone and other timing methods were developed. A relatively complete national time service system was basically accomplished for then on.
In 2001, Shaanxi Astronomy Observatory was renamed National Time Service Center of the Chinese Academy of Sciences.
Construction of the Shaanxi Observatory (Image Credit: National Time Service Center, CAS)
Opening Ceremony for the Shaanxi Observatory (Image Credit: National Time Service Center, CAS)