Research On The Technology Of Single Satellite Positioning Based On Regional Grid

With the rapid development of navigation and positioning system,the demand for navigation and positioning is becoming more and more intense.Satellite navigation and positioning is not only limited to the military field,but also widely applied in automobile navigation,precision timing,meteorological observation,marine rescue,geography survey,manned spaceflight and other fields.It has become an important strategic support for the national economic development.The single satellite positioning,plays a vital role in the satellite navigation and positioning system because of its unique characteristics.However,the corresponding positioning technology is far from mature,leading to serials of problems,such as costs and function.At present,the positioning accuracy of single satellite is mainly concentrated in the 1~10km.Neither single satellite positioning can be used as an auxiliary means of civil navigation and positioning,nor as a supplement for the emergency navigation in the face of major disasters.In this thesis,the characteristics of conventional navigation and positioning system,including GPS,GLONASS,Galileo,BDS and the system model of satellite navigation and positioning are introduced firstly.Then the application background and development trend of single satellite navigation and positioning are studied,the error sources and error propagation characteristics of different location algorithm under the simulation are analyzed.According to the advantages of single satellite positioning,the system model is established.At last the error sources and error propagation models under different positioning algorithms are simulated and analyzed.At the same time,this thesis optimized the performance of the single satellite fast positioning algorithm to improve the positioning accuracy under all-weather,reducing reliance on hardware conditions.In this thesis,the performance of the algorithm is optimized mainly from the following two aspects:1.Improving the calculation speed.Based on the research of geographic information system,the grid model of the integration of space and earth are constructed.Then this thesis designed a grid-enable doppler location algorithm and a grid-enable pseudo range positioning algorithm.Simulation results show that the calculation speed of the new algorithms are faster than the simple doppler location algorithm and pseudo range positioning algorithm,moreover,the beam scanning algorithm are proposed and simulation results show that it improves the calculation speed and the success rate.2.Improving the algorithm accuracy.Although the beam scanning algorithm improves the calculation speed,it has a strong dependence on the satellite position and half power angle.For this,the edge probability weighting algorithm based on beam scanning are proposed sequentially,which can make the beam information plays an equal role in the process of calculation.Simulation results show that the new algorithm improves the calculation speed and the accuracy.Aiming at the problem of all-weather positioning,the fusion localization algorithm based on neural network and beam scanning are designed.Simulation results show that the fusion algorithm has high positioning accuracy and stability under all weather conditions.It presents an effective single satellite positioning algorithm based on global grid,which improved the response of single satellite positioning calculation in this thesis.The positioning algorithm proposed in this thesis can control the error within 5km,under the complex electromagnetic environment and adverse weather conditions.Meanwhile,the accuracy of the single satellite positioning algorithm can reach hundreds of meters with the neural network prediction model.