Satellite Clock Bias Estimation Based on Backward Filtering

A new method was presented for estimating GPS satellite clock biases (SCB) based on a backward filter. It can improve the estimated SCBs precision, when the initial phase ambiguity is not converged. This method overcomes the disadvantage that the ambiguity parameters of conventional Kalman filter does not converge. It is simple and easy to be implemented. The experimental results show that the same positioning accuracy as using the final IGS SCBs can be obtained, when the estimated SCBs are used.