Research And Implementation Of BeiDou High-precision Positioning Terminal Based On ARM-Linux

Beidou satellite navigation and positioning system is a spatial system with independent intellectual property rights, with positioning, timing and short-message communication and other functions, its birth was designed to meet the needs of national security strategy, which has greatly promoted the application of the technology industry. However, as with GPS, the positioning accuracy is an important subject facing the Beidou navigation and positioning system, and is also a hot topic of research. The positioning accuracy of the navigation system is affected by the ionosphere delay, tropospheric delay, satellite clock error, pseudorange error and other factors. There are many methods to improve positioning accuracy, such as adaptive multi-path estimation, differential positioning, multi-system positioning, etc. Among them, the differential positioning using CORS system is a main method, and has gradually become a hot research topic.This paper firstly introduces the principle of satellite positioning and high precision positioning technology, according to the type of high precision positioning technology and their advantages and disadvantages, choose the system used by the Beidou pseudorange differential positioning method in this paper. Secondly, this paper studies the required system hardware environment, selects the TQ2440 development board S3C2440 as the main control chip and TP-LINK wireless network card; analyzes the function of each pin by D3O3 differential positioning module and design its positioning terminal. In the development process of embedded Linux system, the embedded system software environment were built and transplanted to the development board, including BootLoader transplantation, Linux kernel transplantation, file system etc.In the aspect of system application, combined with the D303 differential positioning module serial workflow and Beidou data format, this paper designs the application of serial communication program; it also designs the application system which connected to the JSCORS server through anglicizing the data format of the NTRIP protocol and achieves high precision positioning successfully.In high precision positioning applications, for its application in areas such as transportation, personal location, this paper analyzes the location platform data formats and data communication and location platform, upload positioning information successfully, achieve the purpose of real-time monitor and track playback.Finally, this paper tests and analyzes the start time for high-precision positioning terminal, static positioning accuracy, dynamic positioning accuracy, sensitivity indicators, verify the design of high precision positioning terminal reliability and stability. All the research will show us a broad application value not only in personal locating and transportation but in many more areas.