| Attitude is an necessary navigation information for the satellite vehicle,which is a non-ignorable research point in orbit determination and positioning.Thereby it plays an important role in the military and civilian application domains.Using the GNSS system to determinate the satellite attitude is more convenient and simpler than using INS.And the price is relatively cheaper and the stability of biases are relatively better.With the rapid development of Beidou navigation system(BDS)in China in the past few years,the accuracy of satellite attitude determination is able to improve with BDS and GPS integrated system because that there are a better spatial geometric configuration which reduces the blind area of positioning.This article is based on the theme of GNSS attitude determination.And the main work is as follow:(1)The principle of GNSS positioning with some related problems are introduced in detail.Among that,the altitude angle weighting model and the signal-to-noise ratio weighting model are tested in the experiment of stochastic model.As a result,the accuracies of the precise point positioning using these two stochastic models are better than equal weight model with different degrees.In the Kalman filter robust positioning experiment,it is tested that the residual-based robust Kalman filter can restrain the deformation gross error effectively.The tropospheric delay repairing experiments with the Klobuchar model shows that the RMS values in XYZ directions are increased by 1.5843 m,3.2978 m,and 2.6553 m,respectively.And the troposphere delay repairing experiment with the saastamoinen model shows that the RMS values in XYZ directions are increased by 2.9287 m and 5.9687 m,respectively.(2)The principle of GNSS attitude determination is researched.The direct method and the least square method are mainly introduced and some related experiments are done.The stability and error control ability of attitude angle measurement by carrier is better than pseudorange.The comparison of the attitude angles solution by single-frequency and dual-frequency shows that using the dual-frequency solution is better than the single frequency in the parts of the stability and error control ability.The comparative test between the direct method and least squares estimation to solve attitude angle shows that the standard deviation and the maximum bias by the two algorithms are same generally just with slightly bias.And the stability and error control ability between the two algorithms are roughly equal.(3)Some researches about attitude determination with GPS/BDS combination were carried out,.And GPS,BDS,GPS/BDS combined attitude determination analysis were tested in some open space and simulated occlusion area respectively.The experiment results show that the attitude determination with GPS/BDS combination has a good accuracy.(4)Another experiment research that the attitude result with GPS/BDS combination in dynamic environment.Due to severe occlusion,the observation environment is poor.The attitude angle cannot be obtained well.When driving in an open environment,the GPS/BDS combination is a good way to determine the change in attitude angle with the car driving.The attitude determination experiment of UAV shows that the dynamic yaw angle calculated by GPS/BDS combination accords with the change of flight route roughly,but the pitch angle calculated by GPS/BDS combination has a larger error,which may be due to the influence of vibration on the pitch angle during flight.Finally a GNSS attitude determination software was initially implemented.So some basic functions of positioning and the attitude determination can be performed. |
PDF Full Text Request