Outdoor And Indoor Pseudolite Cooperative Location Technology Research

Global Navigation Satellite System GNSS(Global Navigation Satellite System)is a space radio navigation system.At any moment and place on Earth,the user's receiver can get its exact location as long as the receiver can normally capture and track at least 4 GNSS satellite signals.However,the attenuation effect of the signal in the propagation process is a natural defect of the radio system,which means that when the navigation satellite signal is blocked,for example,when the user receiver is in an urban canyon,a tunnel,a building,or an underground mining area,Satellite navigation signals almost completely disappear,which cannot provide effective navigation and positioning services,which explains the limitations of the application scope of satellite navigation technology to a certain extent.Pseudo-satellite ground-based navigation technology provides an effective solution.Pseudolite collaboration positioning improves the accuracy,continuity,integrity and reliability of satellite navigation systems by increasing the number of observable navigation satellites,optimizing the geometry distribution and configuration of GNSS observing positioning constellations,and enhancing the satellite navigation system effect.Even in the areas where GNSS signals cannot be reached,the Positioning Satellite Network can independently provide navigation and positioning services,thereby increasing the coverage of satellite navigation applications.Therefore,pseudolite technology has very important application research value.However,there are still many technical problems to be solved in pseudolite technology at this stage,such as system time synchronization,signal distance effect and multi-path effect.In view of these technical problems,this paper analyzes the mechanism and presents the corresponding solutions.Pseudolites are deployed in outdoor environment to explore collaborative Beidou navigation satellite positioning experiments.Based on the ability of outdoor pseudolites to establish navigation and positioning constellations,innovative Pseudo-satellites are used in indoor integrated navigation and semi-physical simulation test environment to build indoor GNSS signal links,so as to carry out indoor pseudo-satellite coordinated inertial navigation and positioning experiments.The main contents and results of this paper are as follows:First of all,the architecture and power characteristics of pseudolite signals are analyzed.The problem of "near-far effect" is solved by adopting the signal mode of CDMA + TDMA,and then the near-unaware pseudolite signal system Design.On the basis of the signal research,taking into account the requirements of high-precision time synchronization of the pseudolite network and GPS standard,a transceiver hardware platform with a timing module is designed,and the overall architecture of the hardware and the design scheme of each sub-module are given.The signal transmission test verifies the validity and correctness of the design.It shows that the designed single pseudolite has reached the standard of mass production.Secondly,based on the research of the key technologies in pseudolites cooperative positioning system,a scheme of time synchronization calibration for pseudolites' network is put forward,and an innovative algorithm based on gray particle swarm is proposed to detect and adaptively predict the satellite clock errors.Pseudolite carrier phase double-difference positioning algorithm model,and further put forward a solution based on carrier attitude of the whole week ambiguity fast;study the mitigation effect of multi-path effects,derived based on CNMC model of real-time multi-path delay estimation method The validity and accuracy of the proposed algorithm are verified by applying it to the satellite clock error monitoring experiment.From the perspective of avoiding the mutual interference of the power of adjacent pseudolite signals,the problem of the location of the pseudolite is studied,Network layout.Finally,through the experiment of outdoor and indoor pseudo-satellites,the technical scheme of the pseudo-satellite collaboration positioning system proposed in this paper is validated.For the outdoor pseudolite satellite positioning system,the architecture and components of the system are described.The background operation and control software of the pseudolite positioning system is developed.The deployment of the road bike test site is described.By analyzing the relationship between the pseudolite satellite navigation satellite positioning and navigation satellite independence In order to verify the validity and integrity of the outdoor Pseudolite collaborative positioning system,aiming at indoor pseudolite signal environment experiment,a semi-physical simulation test technology scheme of Pseudolite networking collaborative inertial navigation is firstly proposed.And based on the design scheme,a demonstration system of integrated navigation simulation test environment was set up.The receiver of ultra-tight integrated navigation software was selected as the test object,and the GNSS navigation satellite signal environment was provided by the pseudolite indoor network.Based on a set of ultra-tight integrated navigation software receiver semi-physical simulation test experiment,and the experimental results demonstrate the validity and reliability of the test system.