Demonstration Experiments of a Remote Synchronization System of an Onboard Crystal Oscillator Using “MICHIBIKI”

Two kinds of demonstration experiments have been performed for the Remote Synchronization System of the Onboard Crystal Oscillator (RESSOX) for the first Japanese Quasi-Zenith Satellite System (QZSS) “MICHIBIKI.” In Experiment One, a RESSOX control signal that includes information of the standard time is sent from ground stations and the onboard crystal oscillators (VCOCXO) are controlled to synchronize the arrival of the RESSOX control signal. The maximum synchronization error is 50 ns. In Experiment Two, on the basis of the results of the time comparison between VCOCXO and ground standard time, the voltage applied to VCOCXO is calculated at the ground station and transmitted. The synchronization error of the time comparison is less than 0.3 ns for six days. Moreover, switchover experiments between Okinawa and Tokyo stations were successfully conducted. Although the QZSS is loaded with two rubidium atomic standards, RESSOX is used in future QZSSs. Copyright © 2013 Institute of Navigation.