Estimation Method of GNSS On-Board Clock Short-Term Stability Based on Smoothed Broadcast Ephemeris

It is difficult to obtain precise on-board clock short-term stability for current BDS and Galileo common users since there is no public precise clock data.Based on the analysis of single station estimation method of satellite on-board clock stability,this paper proposes a simple method based on smoothed broadcast ephemeris.The principle of this method is discussed,followed by performance evaluation using GPS data.Compared to IGS final clock product and other two methods namely PE and BE which is based on precise ephemeris and broadcast ephemeris respectively,we conclude that the relative estimation error of the proposed method is less than 10% for average time of 1-800 s,which is consistent with the results of PE method and better than BE method.The short-term stability of all the current BDS on-board clocks(until August 2012) are estimated by this method,with the results of 6×10-12(τ=1 s),2×10-12(τ=10 s),5×10-13(τ=100 s),and 2×10-13(τ=1 000 s).