Application in BeiDou Satellite Clock Offset Real-time Determination with Epoch Differential Model

  Satellite clock offset is an important error source affecting the positioning accuracy, and real-time precise point positioning requests satellite clock updated in real time. The Satellite clock offset can be calculated by epoch difference model and non-difference model. Compared to eliminating ambiguity parameters of epoch difference model, nondifference model covers so many carrier phase ambiguity parameters that its computational efficiency is much slower. Epoch difference model can work out epoch difference of satellite clock offset with high accuracy only using carrier phase observation, and the restored satellite clock offset can retain a certain level. Using epoch difference model can realize real-time solution of Beidou satellite clock offset. The experimental results show that the accuracy of satellite clock offset difference between near epoch by the filter is better than 0.02 ns, and the restored satellite clock offset accuracy is better than 0.25 ns.