Abstract:

In order to obtain high reliability and accuracy of zenith tropospheric delay more quickly,the paper proposes a parameter estimation method.The method chooses epoch-differenced and undifferenced function model and estimates BDS/GPS satellites clock difference using the near time way.45 MGEX tracking stations distributed globally are selected.Initial orbit information of clock difference estimation used the ultra rapid orbit products released by GFZ and used post products as reference values.The experimental results show that the accuracy of GPS satellite clock difference is better than 0.06 ns,and three kinds of BDS satellites clock difference are between 0.04~0.08 ns,which is a little worse than Global Positioning System (GPS).Apparently,the estimated BDS clock difference meets the demands of computing quasi real-time zenith troposphere delay.

Key words: BDS, clock difference, epoch-differenced and undifferenced model, MGEX