Study On The Key Technology Of Navigation Satellite Autonomous Operation Engineering

In order to enhance the ability of autonomous navigation of satellite and solve the practical problems of engineering about satellite autonomous orbit determination and time synchronization, a set of navigation satellite algorithm which satisfying the requirement and the constraints of practical engineering is an important support of autonomous navigation in period of development of Bei Dou satellite navigation system. This article mainly stud ies the key engineering technology of the navigation satellite autonomous orbit determination and time synchronization. Eventually navigation satellite autonomous operation algorithm can satisfy the system constraints. Therefore, how to achieve a reliable, steady and less on-board source navigation operation of navigation satellite is regard as a basic problem of the paper. And research mainly from the following several aspects:(1)According to the actual system, a set of complete algorithm of navigation satellite autonomous operation has been designed, including the measurement data preprocessing, orbit parameters determination, time synchronization and ephemeris autonomous updating. Considering the environment and constraints of navigation satellite on-orbit operation, firstly, inter-satellite dual-way observations process method, based on simplified dynamics, was given. Then a prior dynamics information based method was employed to eliminate the effect results from abnormal conditions, taking into account that outliers in observations or abnormities in dynamics information of a remote satellite may occur in practical. Finally, experiments were given to validate the approach proposal. The results show that not only the practical requirements can be met, but also precise results of autonomous orbit determination can be obtained by utilizing the approach proposal.(2)The paper analyzes the stability and robustness of the Kalman filter of orbit determination, namely the initial value of the state parameters, the model noise variance causing the effect of the convergence and accuracy estimates of the orbit state parameters. The estimation method of the orbit determination filtering model noise, the conditions of divergence and the suppression method of filtering divergence are given in paper. Then the range of the initial value of the filter parameters which come from ground station can be made sure. And In order to increase the correction action of distance measures, retrain the divergence of orbit determination filtering and enhance adaptability of orbit determination algorithm, the adaptive value to adjustment of error covariance matrix of orbit state parameter has been designed.(3) O n the basis of keeping it inherent ephemeris interface, How to achieve ephemeris updating is a ma in content in this paper to reduce the utilization of satellite resource. The interface agreement between satellite and ground station retains the broadcast ephemeris 18 parameters. According to the features of 18 ephemeris parameters, which the perturbation items including long and short cycle term, six kinds of update scheme was designed to update ephemeris parameters from the ground station by orbit parameter of autonomous orbit determination of navigation satel ite.The paper mainly studies the practica l problem of navigation satellite autonomous operation into engineer application, and some progeny has been applied in practical satellite system. Therefore, the study has a significant guidance to build the “Bei Dou-II” navigation system in our country.