Research On Master Control Station Data Processing Of Satellite Navigation System

In the satellite navigation system, navigation information is transmitted to users, which includes ranging code and data code. The later includes broadcast ephemeris parameters, time-error parameter, ionospheric delay corrected parameters and so on. Those parameters are injected to satellite by master control station after data-processing. It is essential to process the data of satellite navigation system if more acute orientation is needed. So, some key problems in the data-processing of master control station are studied in this thesis.In processing distance observations, simulation analysis was made upon the Hatch filter algorithm which was used in pseudo-range smoothing and was compared with other algorithms. Detecting and repairing carrier phase cycle skip is a challenge for precise position. Firstly, some algorithms of detecting outliers and cycle slips were discussed. Then, improvements were made on the algorithm of detecting outliers and cycle slips using Kalman filter in the model of the 3rd order polynomial. Further more, because wavelet transform has a good local property, carrier phase data can be divided into high frequency part and low frequency part by wavelet transform. Improvements also were made on the algorithm basing on Kalman filter and wavelet. Eventually, simulation researches were made on these two improved algorithms.Ionospheric delay has an important influence on user's navigation and orientation. Three representative ionospheric delay models were introduced. Improvements were made on Klobuchar model by adding its parameters from 8 to 15. Also, simulation researches were made on its prediction accuracy. At the same time, comparison was made between spherical-harmonic expansion and grid-based ionospheric model. Time synchronization between satellite and the earth is an essential problem in ensuring satellite time benchmark and orientation precision. Least square method was introduced to time-error parameter fitting basing on time-error frequency model. Kalman filter also was introduced to time-error parameter estimation and prediction. The results of these two algorithms were analyzed contrastively.Using motion equations and kinetic parameters, observation equation and state equation were deduced which were based on in satellite orbit determination researches by introducing generalized kalman filter. A batch algorithm based on least square method also was introduced. In the end, the orbit determination algorithm basing on generalized kalman filter was validated and analyzed by simulation.