Research On Pseudolite System For Beidou Based On Independent And Dynamic Aircrafts Configuration

Global Navigation Satellite System is able to provide navigation service of all-weather,globalcoverage and high precision.However,low data output rate,poor reliability in dynamic environmentand weak adaptability and coverage are its shortcomings.BeiDou Navigation System will also face theabove problems which is to navigate around the global in2020. Pseudolite technology is one of theeffective ways of the problems.Based on this point,the thesis studied the construction of pseudolitesystem deeply and put forward the pseudolite system for BeiDou based on independent and dynamicaircrafts configuration in background of BeiDou Navigation System using in some combat region.Thesystem composed of1airship and4high altitude and long endurance unmanned aerialvehicles(UAVs),which provided navigation service to ground users in the area of120km120km.Firstly, pseudolite networking was studied by way of combining with empirical method andGenetic Algorithm. Several common static configurations were presented at first and the best one wasobtained by empirical method.Then we determined the parameters of the configuration by GeneticAlgorithm on the premise of optimal performance of the pseudolite constellation and analyzed thedynamic configuration.Finally, independent and dynamic configuration was used in this thesis.Secondly,integrated positioning of pseudolites based on SINS/BD/CNS/message inter-UAVs wasresearched which was important part of the pseudolite construction and also core content of thethesis.The integrated positioning system added Celestial Navigation System because of the lowerattitude precision of SINS/BD integration.There were many UAVs in the pseudolite system,so the wayto improve position precision based on the message inter-UAVs was put forward that the abundantmessage was fully used.Lastly, the thesis simulated and verified the integrated positioning systembased on SINS/BD/CNS/message inter-UAVs in manner of federal filtering.Finally,simulation of users’ navigation precision of the pseudolite system for BeiDou was done.Itanalyzed the cause of the positioning error in detial.In order to eliminate the clock error ofpseudolites,weaken other common error and increase navigation precision,differential technique wasintroduced to the pseudolite system.Simulation results show that the pseudolite system is able toprovide moderate navigation service instead of BeiDou Position System when the latter is unavailableto users.