Research of the actiive atomic hydrogen clocks at Shanghai Astronomical Observatory

Support from the Chinese Academy of Sciences and the General Armament Department, certain technology improvement and enhancement of atomic hydrogen clock was effectively carried out by Shanghai Astronomical Observatory under the promotion of BD, lunar exploration, deep space tracking projects. The atomic hydrogen clock's reliability and performance have been greatly improved. The developed atomic hydrogen clocks play an important role in some national scientific experiments and military projects. Performance evolution shows that the active hydrogen clock's stability is better than 2E-15/day, temperature coefficient is better than 5 E-15/°C.