Research Of Supporting Navigation Technologies In Beidou/GPS Dual-mode Navigation Terminal

With the rapid development of satellite navigation system and the extensiveapplication of navigation terminal, all the application fields put forward higher requestfor the service performance of navigation system, and hope to get high precision, highdynamic real-time, high reliability, and high security orientation navigation service.Beidou Satellite Navigation System, which is researched and developed independentlyby our country and is controlled and operated independently, has the strategic advantageof high reliability and safety. Currently, GPS which is the most widely used globalsatellite navigation system has many advantages such as wide coverage range, highpositioning accuracy and strong real-time. The effective combination of Beidou andGPS can significantly improve the application level of the navigation system, and meetthe higher requirement for positioning and navigating.According to the development situation of the satellite navigation terminal industryin China, and the application requirement of domestic navigation terminal, severalimportant supporting technologies involved in the Beidou/GPS dual-mode navigationterminal R&D are studied in this thesis.â‘ The basic principles about Beidou-I and GPS are analyzed in this thesis, and theembedded system of dual-mode navigation terminal is designed combining withembedded technology. According to the requirement of dual-mode navigation terminal,we establish an embedded software and hardware platform including building andconnecting of each module in hardware platform, transplanting of BootLoader, Linuxkernel and file system, and the establishment of the graphical interface platform insoftware platform.â‘¡This thesis makes a detailed analysis about the data transmission protocols ofBeidou and GPS, and serial communication technology of Linux. According to thecharacteristics of Beidou and GPS data transmission, this thesis proposes a method ofreading dual-mode navigation data based on I/O multiplexing, and implements the datareceiving and resolving functions for Beidou/GPS navigation.â‘¢The structure and data format of MIF/MID are analyzed in this thesis. We buildthe mathematical model of map display according to the research in map displayprocess of terminal. And we further propose the hierarchical display strategy of map, and the hierarchical rule of map data. According to the strategy and rule, we haveimplemented the function of map data organization, reading and drawing.â‘£In this thesis, we test each functional modules of the navigation terminal andshow the results of the system. According to the test result, we analyze the shortages ofthe navigation terminal and show the improvement of terminal.In a word, the relatively complete and in-depth study about supporting navigationtechnologies in Beidou/GPS dual-mode navigation terminal are fulfilled in this thesis,and the proposed design scheme and solution have been evaluated by the experiments.This study presents reference value with regard to the research and development workof navigation terminal in forms of miniaturization and low-cost dual mode.