Research On Data Processing Method Of Spacecraft External Ballistic Measurement

In recent years,the expansion of aerospace applications,the improvement of flight test mission requirements and more complex space environment have brought great challenges to the Space TT&C system.With the rapid development of the external measurement system,many types of external measurement equipment are gradually widely used,which puts forward more stringent requirements for the method and accuracy of spacecraft external measurement data processing.Therefore,in order to accurately describe the orbit of the spacecraft and obtain high-precision ballistic parameters,it is necessary to study the high-precision external ballistic measurement data processing methods that can be applied to practical projects.Based on the external measurement system composed of multiple devices,this thesis mainly studies three aspects of external measurement data preprocessing,real-time data fusion processing in non-linear non gaussian system,and post event data comprehensive processing in ballistic layer.The specific research work is as follows:(1)Aiming at the problem that the coordinate systems used by different measuring equipments are not consistent and the time benchmark is not uniform,this thesis studies the spatial alignment model between the polar coordinate system and the launch coordinate system,and analyzes the interpolation time alignment method and the curve fitting time alignment method theoretically.It is found that the estimated value obtained by the curve fitting method will be closer to the real value and have greater advantages.(2)Aiming at the system error in the field data,this thesis analyzes the main system error sources of pulse radar and photoelectric theodolite,and establishes the corresponding system error model.Aiming at the gross error in the external measurement data,a Nonlinear Multi-Point Prediction and Evaluation model(NMPPE)based on least squares and time polynomial is established,and an outlier discrimination and filling estimation algorithm based on this model is proposed.The effectiveness of the algorithm is verified by testing the actual data.(3)Aiming at the multi-source characteristics of exterior ballistic measurement data and the nonlinear non-gaussian problems faced in real-time data fusion processing,using the Unscented Particle Filter(UPF)as a tool,two real-time data fusion processing methods are perfected,which are convex based on the recommended distribution.Combined fusion estimation algorithm and sequential filtering fusion estimation algorithm.Simulation results show that these two fusion strategies are feasible and effective,and the accuracy of orbit estimation has been significantly improved(4)Aiming at the problem of comprehensive data processing after the ballistic layer,the accuracy evaluation of the external measurement system,the accuracy estimation of the ballistic parameters under the RAE measurement system were studied,and the weighted fusion algorithm of the ballistic layer data was implemented.Finally,the real radar was measured in a flight test.The data has been verified by simulation,and the results show that the processing algorithm can obtain the expected data processing results(5)In order to apply the research work better in practice,based on MATLAB platform,this thesis designs and develops the external ballistic measurement data processing software system which integrates the functions of data acquisition,data preprocessing,real-time data and post event data fusion processing,and evaluation report generation...