History of Science and Engineering Annotation << Back System of Time-and-Frequency Synchronization of Quasar Network Vytnov A.V. Ivanov D.V. Zhukov E.T. Smolentsev S.G. Yakovlev V.A. Results of long-term works on creation and perfection of the system of time-frequency synchronization of Quasar radio interferometry network are presented at this publication. It is necessary to solve the problems of coherence frequency conversion and simultaneity of the registration of the signals in remote radio telescopes for observations of cosmic radio sources in interferometry modes with super long bases. For the decision of problems of coherence is required to provide a high stability frequency of heterodyne and phase stability of the receiver-transform paths. All frequency conversions on the radio telescopes are synchronized to a reference hydrogen standard of frequency. Support of phase stability is achieved by the introduction in the path of the receiving system picosecond pulse and control delays of their harmonic components selected on the output of the radio path. The time scale of radio observatory is referenced by hydrogen standard also. Preliminary synchronization of time scales with microsecond accuracy is necessary for ensure of a simultaneity of registration of signals. It is achieved by using of signals of satellite GPS and GLONASS navigation systems. Thus, the system of time-and-frequency synchronization provides functioning of space-separated radio telescopes with independent heterodynes as uniform faze measurement radio system and is a necessary element of each observatory of the Quasar network. Keywords: system of time-and-frequency synchronization; time scale; H-maser; picosecond pulse; phase stability. Contacts: E-mail: vytnov@yandex.ru Pp. 84-90.