Research On Key Technologies Of Multi-constellation Integrated GNSS Navigation System

Multi-constellation integrated navigation is the developing trend of the satellite navigationtechnologies. Therefore, thinking about the GPS, GLONASS, GALILEO, BEIDOU, the four mainglobal satellite navigation systems, are to complete their modernization and overall constructionrespectively in the recent ten years, the theories on the key navigatiion technologies of the futuremulti-constellation integrated system are urgently needed and would be researched forward-looking inthis paper.Firstly, the time and space coordinates of GPS, GLONASS, GALILEO, BEIDOU were analyzed,and spatial and temporal unified program, particularly a time-unified approach based on UTC (BIPM)was proposed, which laid the prerequisite foundation for multi-constellation integrated navigation.Secondly, the main working flow of the modern multi-constellation navigation was designed andsome parts of the modern multi-constellation positioning algorithms were initially deduced, whichestablished theoretical feasibility of the multi-constellation navigation system.Thirdly, the configurations of modern GNSS constellation space were listed and presented.Subsequently, based on this constellation configuration, judging from the DOP value and the integrityas two indicators, the performance of the modern GNSS multi-constellation navigation system wasanalyzed and suggestions for improving the system were proposed after then, which provided thetheoretical reference of for the optimization of the multi-constellation navigation system.What’s more, the key technical problems of high-precision positioning and attitude determining ofmodern multi-constellation systems, the ambiguity solving problem, was also researched in this paper.The traditional GNSS ambiguity algorithm and the TCAR algorithm based on the signals of threefrequencies were analyzed, which clarified the advantage of TCAR algorithm for improving modernmulti-constellation system’s ambiguity resolution. Further, for the low success rate of TCAR, basedon a short baseline double difference model, an adding small search spaces in different classes methodfor improving the TCAR were proposed, and the simulation tests were done to prove the algorithmcould greatly improve the TCAR algorithm’s success rate, and multi-constellation navigation systemcould also strengthen the performance of the improved TCAR.Finally, the multi-constellation navigation simulation platform with animation effects wasdeveloped, and the overall framework, main modules and operation methods of platform were statedin details, which provided the convenience of data analysis for the modern multi-constellationnavigation research.