Remote Synchronization Method for the Quasi-Zenith Satellite System

This book presents a novel satellite timekeepingsystem which does not require on-board atomic clocksas used by existing navigation satellite systems suchas GPS GLONASS or the GALILEO system. Thisconcept is differentiated by the employment of asynchronization framework combined with lightweightsteerable on-board clocks which act as transpondersre-broadcasting the precise time remotely provided bythe time synchronization network located on theground. This allows the system to operate optimallywhen satellites are in direct contact with the groundstation making it suitable for a system like theJapanese Quasi-Zenith Satellite System QZSS. Lowsatellite mass and low satellite manufacturing andlaunch cost are significant advantages of this novelsystem. Two possible implementations of the timesynchronization network for QZSS are presented.Additionally the problem of satellite communicationinterruption is analysed and a solution is presented.Finally a positioning and timing quality analysisaimed to provide understanding of the actual timingquality requirements for QZSS is presented.