Research On Reliabiliyt Of Mobile Phone A-GPS Navigation Performance

With the growing power of mobile phones,the precise location of mobile phones has become one of the needs of People's daily life.Mobile phone A-GPS positioning is the first choice of mobile phone positioning due to its fast positioning speed and high precision.However,in the state of motion,A-GPS positioning has the disadvantages of low positioning accuracy,and there is less research on mobile phone A-GPS navigation performance in China.At present,the mobile phone cannot directly acquire the original observation data by positioning,while the performance of MT3333 module is the same as that of mobile phone positioning,supporting EPO auxiliary positioning,and supporting the acquisition of original data.Based on this,this paper takes MT3333 module as an example to study the reliability of a-gps navigation performance under dynamic conditions,and provides reference for further improving the positioning accuracy of mobile phone a-gps.The main contents are as follows:1.The navigation performance of the MT3333 module is analyzed.In static and dynamic two environments,the positioning performance of MT3333 module is equivalent to the A-GPS positioning performance of mobile phone,and the mobile phone A-GPS positioning interface based on Android system is designed.2.The positioning accuracy of the MT3333 module is improved through single-base station pseudo range differential and QianXun location service.From the experimental results,the MT3333 module's plane accuracy under the single base station pseudorange differential is 2.131m under the motion state.The plane accuracy under service is 1.576m,and both have greatly improved compared to pseudorange single point positioning.3.The pseudo distance single point positioning accuracy of the MT3333 module is improved by the research of three kinds of weights model of the equivalent weight model,the height angle model and the Helmert variance component model.The accuracy of the pseudo distance single point positioning of the MT3333 module based on the Helmert variance component model is the best,and the pseudo distance single point positioning precision based on the height angle model is obtained from the experimental results.It is superior to the pseudo range single point positioning accuracy based on equal weight model.4.The relationship between the speed of MT3333 module and the performance of navigation is studied.The position differential velocity measurement is improved,and the accuracy of Doppler velocity measurement and high-precision position difference velocity measurement is compared and analyzed.The analysis of walking and vehicle experiments shows that there is a correlation function relationship between the positioning performance and speed of the MT3333 module,but the location data acquisition rate is reduced at a higher speed,and the applicability of the relationship model between the positioning performance and the speed is reduced.