Research On Key Technologies Of Integrated Satellite Communication, Navigation And Remote Sensing System

With the gradually development and improvement of the Global Navigation Satellite System, China is preparing to complete an independent satellite navigation system—Beidou navigation and positioning system. Up to now, Beidou Navigation Satellite System has just launched 16 satellites. Therefore, there are some limitations in some areas, which is unable to complete the positioning or the positioning performance is poor because of the lack of visible satellites or physical terrain and other reasons. In this thesis, the principle of the integration of communication system, navigation system and remote sensing system is proposed. With the Beidou system, iridium system and remote sensing system as an example to illustrate the analysis, the integrated system achieves the goal of navigation enhancement, which can not achieve the advantages of single constellation navigation system in many aspects, such as the number of visible satellites, working efficiency, reliability and positioning accuracy.This thesis puts forward two kinds of integrated methods, which are the simple fusion and forward integration of the Beidou / iridium / remote sensing fusion system. The good performance of the fusion system is analyzed from three aspects: the selection algorithm, the autonomous integrity detection and the integer ambiguity resolution. The main research results are as follows:(1) A new algorithm of successive selection that based on the selection of the height angle and azimuth angle is proposed, and improved algorithm to make it suitable for the Beidou/iridium/remote sensing fusion system by means of expanding the theory. Under the premise of ensuring the positioning accuracy, the computation quantity is obviously reduced and the positioning efficiency is improved.(2) Satellite selection algorithm that each satellite system is arranged and combined is proposed, through a large number of experimental simulations, we summed up the best number of each satellite system of Beidou/iridium/remote sensing fusion system and the Beidou/iridium system, the best way to select the number of satellites. This algorithm has provided a reference to improve the real-time performance of positioning.(3) Analysis autonomous integrity monitoring of fusion system, The availability of RAIM has been improved., simulating fault detection rate and fault detection rate of fusion system. And through the random search algorithm to study the multimode system under multi satellite fault recognition, effectively improves the autonomous integrity detection performance.(4) Due to the increase of the number of visible satellites in the integrated system, the dimension of the integer ambiguity vector becomes higher, and the computation speed is increased, so the fuzzy degree vector can be divided into two parts: the main fuzzy degree and the fuzzy degree.Analysing and finding the best LAMBDA algorithm, by the best LAMBDA algorithm used in the main ambiguity solution, and solve the calculation from the fuzzy part, to improve the convergence.