Research And Simulation On Positioning Algorithms Based On Integrated Navigation System

The combined positioning and navigation system which based on GPS, GLONASS,and BeiDou System is one of the hot topics in satellite navigation research field at present.Again, currently, the measurement data of the satellite navigation system contains a lot oferror factors that affects the positioning accuracy. Furthermore, it may also be led to newerrors in the observer value between the different types of satellites. Thus, it’s difficult toanalysis the result of positioning of the integrated navigation system. Therefore, it’ssignificant to simulate the different single system and to integrate navigation system. Thepresent paper performes the simulations of the single point positioning and the relativepositioning of the single system and the integrated navigation system by using the matlabprogramming language, as well as verifies the algorithm and the feasibility of the Helmertvariance component estimation of the integrated navigation system at the meantime.Firstly, the principle of the satellite motion of satellite navigation system is introducedin this paper. The simulation program language is written according to the constellationparameters of the GPS, GLONASS, BeiDou system. In additional, comparing the observedvalue with the simulation results that contains the simulating error, it’s validity is verified.Secondly, the positioning principle of satellite navigation system and the algorithm of theintegrated navigation are recommended in this paper. Meanwhile, the author makes acomparison between the single system and integrated system about the positioning accuracy.What’s more, the positioning accuracy of the single system and integrated system that hasbeen affected the random error is judged by comparing the before and after result of addingthe random error in the single system and integrated system. Finally, feasibility analysis ofthe model of the integrated navigation system which is based on the Helmert variancecomponent estimation is conducted.After theoretical analysis and experimental study, the conclusion of the present paperare as follows：1.Analyze the result of the compare between the pseudorange of simulation and theobserved value, besides the satellite cannot be observed by the receiver in some epochs, thedifference between the two value both are in100meter, which prove that the validity of thesimulation to the pseudorange observation.2. Under the condition of the same observation, the simulation result is closed to theobservation result, which confirms that the feasibility of the simulation. According to the comparison of the before and after result of adding the random error, the observation resultof the single system is easier to be affected than the integrated system. Hence, in such cases,the positioning accuracy of the integrated system by using the combined algorithm is higherthan the single system. Meanwhile, the result of the combined algorithm has been moredifficult affected than single system by the random error. In the analysis of the simulation,the difference between the before and after adding random error seems very slight.3. By comparing the relative positioning model and algorithm calculating result ofsingle system and the integrated system, the RMS of the single system calculatingdifference of x, y, z axis reaches the centimeter-level, and additionally, the RMS of theintegrated system calculating difference which based on using the Helmert variancecomponent estimation reaches the millimeter-level. It indicated that the Helmert variancecomponent estimation algorithm is feasible.