Abstract:Based on an explanation of the definition of GNSS system time offsets, we build a polynomial predicting model that is suitable for BDS/GPS system time offsets. Some improving measurements, such as selecting the quadratic term parameter, determining a few prominent periodic terms and choosing the weight function of observations, are applied to above model. Simultaneously, on the basis of the predicting characteristics of AR model, we build the combined time offsets predicting method of the polynomial and AR models further. 〖JP2〗The results of simulations show that the single day predicting precision of the new model is superior by 0.4ns, which is significantly better than other traditional methods