Study On The Methods Of Diagnosis And Correction Of Ill-condition In GPS/BDS Joint Positioning

In geodesy, due to the presence of normal equation ill-posed problem, making the data processing presents morbid adjustment models,the nature of the valuation parameters of least squares is significantly deteriorated, and the resulting solution is unstable. Conduct research on the morbid, you first need to determine whether there is not the normal equation morbid, if there is to be processed on the morbid, the instability of the solution to a minimum. This paper analyzed the project common law equation morbid diagnostic methods and treatment measures, comparative advantages and disadvantages, the valuation to effectively improve the quality, Relative stability and accuracy of solution is the least squares estimation are improved effectively.For the improvement of ill-condition equation, three aspect studies were done: Firstly based on conventional ill-condition process, by comparing the precision of the error transferring method and least squares estimation, ridge estimation, truncated singular value, limitations of these methods are analyzed; Secondly according to the property of the ill-condition equation, learning Tikhonov regularization theory, more effective ways to improve the property of the ill-condition equation have been found. And propose several new methods which treat ill-condition. Thirdly making depth research for error transferring method, according to the method of the second study, the error transferring matrix is constructed to transfer error, and compare the accuracy to obtain high accuracy of ambiguity float solution. From the perspective of ambiguity searching method, a variety of the root-mean-square matrix error based the error transferring matrix are explored to search ambiguity, comparing fast ambiguity solution approaching method and LANBDA methods to resolute ambiguity.Lastly combining these two aspects to make integration of GPS ambiguity resolution, examples using matlab programming to compare positioning accuracy is analyzed.Based on the study of ill conditioned GPS correction method based on, explore the application of pretreatment method in compass and GPS/BDS joint positioning method commonly used equations are ill posed, focuses on to improve pathological method effect on ambiguity resolution. Analysis of the existing methods,on the basis of error transfer method is proposed based on the error transfer method of new research to improve the ambiguity solution in the presence of morbid, improve ambiguity solution success rate, so as to improve the accuracy of joint location. Experimental results show that, after GPS/BDS fusion, the structure of the coefficient matrix is not obviously changed due to the serious ill conditioned effect of the single system, and the GPS/BDS joint positioning is beneficial to the fast convergence of the fuzzy degree of the Beidou system.