Research Activities on Standard Time and Frequency Signal Dissemination Using Communication Satellite Links

Abstract

Standard time and frequency signal dissemination systrms using communication satellite links developed at the National Institute of Metrology(N1M) are described. In our country the standard time and frequency signal dissemination techniques via satellite have been developed since 1979. We have done some researches on standard time and frequency signal dissemination via satellites surh as SYMPHONIE , IS-V, and chinese experimental communication satellite STM-1. Based on the results of these researches, The domestic standard time and frequency signal dissemination system U S P S the chinese experimentat communication satellite STM-1 and broadcasting communication satellite in addition to the ordinary links of ground TV and Loran-C. The systems for international time and frequency transfers depend on the spacr techniques of the The experiments were used one-way and two-way techniques. using spread-spertrum techniques thr precision of less than Ins (0.15111) and an acrurary of Ions (3m) have been obtained. GI'S, loran-C and other system.