Precipitable Water Vapor Retrieval Method Based On Ground-based GNSS In Shenyang Area And Its Application

Continuous operation reference station(CORS)is a satellite positioning service system with wide coverage,small terrain limitation,long communication distance and high precision.In recent years,CORS system has been gradually established in various provinces and cities to meet the needs of national infrastructure informatization.Among them,the application of CORS in meteorology is developing rapidly.At present,the main application of GNSS in meteorology is to retrieve the Precipitable Water Vapor(PWV).Water vapor is an important factor in climate change.It is of great significance to study the influence of atmospheric water vapor change on meteorology.Therefore,based on the observation data of CORS center in Liaoning Province,this paper firstly collected the sounding data of Shenyang station in 2018,established a weighted average temperature formula suitable for Shenyang area,and then compared the accuracy with Bevis formula.At the same time,the surface meteorological data of Shenyang in July 2018 were collected.After calculating PWV according to relevant principles,PWV was compared with GPS and radiosonde data respectively,and then compared with root mean square Error,average error,correlation coefficient and significance test were used to evaluate the accuracy of PWV,results are as follows:Taking the weighted average temperature calculated by sounding station as the true value,the root mean square error(RMSE)of the fitting formula is 4.55 k,the average difference bias is 3.59 k,the root mean square error(RMSE)of Bevis formula is 5.24 k,and the average difference bias is 3.90 k.The error of fitting formula is smaller than that of Bevis formula,which is more suitable for Shenyang area.The difference between GPS/PWV calculated by the fitting formula and PWV calculated by radiosonde station is very small,and the accuracy is high;however,the surface water pressure method is affected by the observation conditions,and the difference between the surface water pressure method and the sounding station's PWV value is large and the accuracy is low.Then,after verifying that ECMWF data can replace sounding data to solve PWV as the truth value,beidou data is used to solve PWV of Shenyang,Benxi,Fushun and Liaozhong stations.Compared with ECMWF data and GPS/PWV of the same period,it is found that: Beidou system inversion PWV and GPS system,sounding station calculating results have good consistency,and regarded as the true value of ECMWF root mean square error is 3.26?4.13 mm,the average error of 2.58?3.31 mm,the correlation coefficient is 0.86?0.92,compared with GPS/PWV,affect the Beidou system accuracy,GEO satellite space atomic clock is the cause of error signal precision error is bigger,and GEO and IGSO satellites exists jump conditions.