Abstract: With the number of satellites and ground monitoring stations increasing，a lot of GNSS observation data will be produced every day.Making the use of all data to determine the precision clock error will certainly affect the efficiency of its solution.In order to determine the precision clock error by the use of different stations,and clarify the effect of the precision clock error on the calculation accuracy and computation speed jointly by GNSS multi system,the observation data from MGEX station and iGMAS station with receiving ability of four systems are adopted to calculate the satellite clock error.According to the calculation results,the relationship between the number of stations and the solution efficiency and the relationship between different solution strategy and the solution efficiency are analyzed.The results show that when the number of stations increases to 50,the time-consuming is maximumly increased by 39%,and the precision of corresponding clock error is only improved by 10.5%.The two-step solution strategy is improved by 48.02% compared with one-step method,while the time-consuming is reduced by 41.82%.

Key words: Satellite clock error, No.3 Beidou satellites, Number of stations