Research On Positioning Technology Of Navigation Receiver Base On Differenced Carrier Phase

With the establishment and perfection of different global satellite navigation systems,the satellite navigation field in the future will enter the time of multi-system integration.The combination of multimode global satellite navigation systems will become the main direction of high-precision navigation and positioning.Cycle-slip detecting and fixing and integer ambiguity resolution are the core problems of high precision positioning.To deal with these two problems,this paper starts with the mathematical model and working principle of the carrier phase differential positioning system,and sums up the errors and corrections of the satellite receiver data of observation.Based on those above,the classical theory method of the detection of cycle slip and the integer ambiguity resolution are studied and analyzed,and finally it is improved to make it more adapt to the multimode positioning system.In this paper,the main research content includes the following three aspects:Firstly,the GNSS mathematical models,error sources and correction models of carrier phase differential positioning are analyzed in detail..For the properties of special combinations of raw observation data in the precision positioning in front data processing?cycle slip detecting and repairing and Integer ambiguity calculation,the paper analyzes the application field of wide lane combination?the narrow lane combination?ionosphere residual combination and the ionosphere-free combination to lay theoretical foundation for following research.Secondly,the common cycle slip detection methods are studied from the point of dual-difference carrier phase observation.For different satellite system phase noise is different,the threshold determined by the prior value has been unable to cope with multimode navigation data cycle slip detection,this paper used adaptive dynamic threshold to improve MW method and ionosphere residual method.With the improved two methods,a data preprocessing scheme with both cycle slip detection and fixing is constructed together with no ionosphere method and no geometry combination repairing cycle slip.It is shown from the measured data of the observation station that the combined cycle-slip detection scheme of the dynamic threshold can detect all cycle slips accurately and distinguish gross error and cycle slip accurately.At last,through the comprehensive analysis and comparison of the classic ambiguity resolution methods,the method of Least-squares Ambiguity Decorrelation Adjustment(LAMBDA)with excellent performance and reliable performance is selected as the following object of study.This paper systematically introduces the LAMBDA method,and focuses on the search space and search strategy in the solution of the integer ambiguity.A new ambiguity search method is proposed to solve the shortcomings of the integer least squares method,which uses traditional empirical value to determine the searching space,which is time-consuming and easy to fail in the multimode multi-frequency positioning system's high-dimensional computing environment.This improved method balances the fixed success rate and the computing time of integer ambiguity by changing the searching range of Bootstrap method.Experiments show that the proposed method can reduce the fixed time of ambiguity while keeping the approximate fixing success rate compared with integer least squares method.