The method of earth rotation parameter determination using GNSS observations and precision analysis

Abstract

Based on the principle of GNSS observation, the linear observation equations of earth rotation parameters (ERP) estimation using GNSS data are deduced. The general solution and precision evaluation function are obtained. According to the precision evaluation function, the major factors of effect ERP solution precision are analyzed. One is the geometric distribution of the satellites relative to the station; another is the geometric distribution of the stations relative to the geo-center. It is proved that ERP will not be solved if using one GNSS station. The solution precision of ERP will be the best when the vectors of two stations to geo-center are orthogonal, if two stations are used. For testing ERP estimation precision using GNSS data, two weeks GPS data from 295 and 21 IGS stations are processed, respectively. The results show that the precise ERP can be obtained whether 295 or 21 stations data are used, when the stations rational distribution. The estimation precisions of pole motion and length of day parameters are better than 0.04 mas and 0.03 ms respectively, where the results of IERS are taken as the reference values. © 2013 Springer-Verlag Berlin Heidelberg.