Time series noise analysis of GPS vertical observations in northeast margin of Qinghai-Xizang block
In order to futher study the optimal noise model for global positioning system(GPS)station vertical displacement sequences at the northeast margin of Qinghai-Xizang block and the effect on station vertical velocity estimation,the paper proposed time series noise analysis method of GPS vertical observations in northeast margin of Qinghai-Xizang block:the GPS coordinate time series from 27 crustal movement observation network of China(CMONOC)reference stations in the northeast margin of Qinghai-Xizang block were selected,and different noise models were used to analyze the vertical displacement time series of the stations;then,the differences among the optimal noise models determined by Akaike information criterion(AIC),Bayesian information criterion(BIC),Bayesian information criterion with time penalty(BICtp)and Bayesian information criterion with correction(BICc)and their effects on vertical velocity estimation were discussed.Results showed that the optimal noise models determined by AIC would be mainly:generalized Gaussian Markov noise(GGM)+auto-regressive moving average of order 1(ARMA1),GGM+white noise(WN)and WN+flicker noise(FN),accounting for 29.6%,22.2%and 18.5%of the total number of stations,respectively,while the optimal noise models determined by BIC,BICtp and BICc criteria would be mainly WN+FN,accounted for 74.1%,66.7%and 70.4%of the total number of stations,respectively,followed by GGM,accounting for 22.2%,22.2%and 14.8%of the total number of stations,respectively;moreover,it was found that BIC,BICtp and BICc would have greater influence on GGM+ARMA1 and GGM+WN models in the process of determining the optimal noise model,and BICc would be more sensitive to random walk noise than BIC and BICtp;furthermore,there would be some differences in the drooping speeds and uncertainties at the northeastern margins of the Qinghai-Tibet block determined by different information criteria,but the overall trend of drooping could be basically the same,with a decreasing trend at the southwestern stations and an increasing trend at the northeastern edge stations,meanwhile the magnitude of the increase or decrease would be relatively small.
global positioning system(GPS)time seriesnoise modelmaximum likelihood estimation(MLE)information criteria
NETL
NSTL
万方数据
