Analysis Of Coordinate Time Series Of Regional CORS Stations In Henan Province

Henan Geological Continuous Operation Reference Station System(CORS)is the first application of CORS system in geological field,on the one hand,establish and maintain a high-precision 3D datum in Henan,provides precise positioning and orientation services for economic construction,and provides a precise reference datum for regional geodynamics and kinematics and other basic discipline research.On the other hand,it provides the mainstream geological work service to the users in the geological field in Henan Province.Since the geological CORS in Henan was put into use in 2009,due to various factors such as geological structures,plate movements and human activities,and the location of CORS sites is in the process of dynamic changes.Based on the above reasons,it is necessary to analyze the coordinate time series of Henan Geological CORS system and obtain the velocity field for the system evaluation and regional stability.This paper analyzes the noise characteristics and velocity fields in the Henan region based on the three-year observation data from 2016 to 2018 from Henan geological CORS,Henan peripheral datum stations and IGS datum stations in China,and the specific research contents and results mainly include:(1)Analyzing the quality of the original observation data of the geological CORS benchmark stations in Henan and Henan peripheral datum stations.The results show that the data completeness of 52 benchmark stations is higher than 95%;the Mp1 and Mp2 values of the multipath effect of L1 and L2 carriers are lower than 0.8;the quality of observation data is good;and the benchmark stations operate stably from 2016 to 2018.(2)Baseline solution and net adjustment were performed on the observed data to generate GPS coordinate time series.The standardized error of root-mean-square of the solved baseline is less than 0.2,and the weighted error of root-mean-square of the repeatability test is very stable and small in all three directions of NEU,so the solving results are good.The generated station coordinates have an obvious overall trend in the horizontal direction with little relative motion,and the law is not obvious in the vertical direction.After generating the original time series,the gross errors are first filtered and eliminated by pauta criterion,and then the missing parts of the time series are interpolated by cubic spline interpolation,a clear and stable coordinate time series is generated.(3)Using maximum likelihood estimation method to henan geological CORS is used to estimate the optimal noise model,calculated the WN model,WN+FN model,WN+RW model and WN+FN+RW model 4 kinds of noise model combination in henan area of maximum likelihood estimate,the results after statistical analysis.It is determined that the most suitable noise model in Henan province from 2016 to 2018 is the white noise flicker noise model.(4)Based on this calculation,the uncertainty of the velocity field of Henan and its surrounding areas and the velocity of reference stations are obtained.The results show that the horizontal direction of Henan region moves southeastward as a whole,and the average rate is31.66mm/a to the east and 10.77mm/a to the south;the vertical direction shows obvious regional characteristics,the South and North showed an upward trend,while the West,central and east showed a downward trend..The geological CORS system in Henan province is stable from 2016 to 2018,and the horizontal direction of each datum station is consistent,which reflects the movement trend of its plate,and there is no obvious relative movement among stations.