Research On The Construction Of Global Measurement Space And Its Accuracy Control Method

In the field of large space coordinate measurement,the combined measurement method is used frequently to control the whole measurement space,because of the large space,high precision,complex structure characteristics and changeable environment conditions.The combined measurement method includes the multi station measurement of single measuring equipment,the simple integrated measurement of the fusion of various measuring devices,and the combined measurement of the combination of the long distance global control and the close range terminal measurement.The combined measurement method,which combines global control and terminal measurement,can be used to control the overall measurement and local observation in the measurement space.According to the measurement requirements of each measuring part,this method makes full use of the performance of measuring devices.It makes series connection and optimization combination of different measuring devices.Finally,by integrating and integrating measurement data,the purpose of improving measurement efficiency and controlling measurement accuracy is achieved.In the whole combination measurement process,as a basic work,the global control survey plays a crucial role in the control of measurement accuracy.In this paper,a high precision total station instrument is used as a tool.Aiming at the key technology problems involved in the construction and accuracy control of the global measurement space,the main research work is as follows:(1)The common methods of point error measurement are summarized.According to the measuring principle of the total station instrument measurement system,the distribution law of the point position measurement accuracy in the global measuring space is simulated and analyzed by mathematical analysis,mathematical statistics and ellipsoid method using the Matlab interface design and programming.(2)The seven parameter transformation model of coordinate transformation is introduced.The results of preliminary transformation using several commonly used coordinate transformation methods are compared and analyzed;Then the construction process of transfer accuracy distribution model is introduced.The unconstrained optimization method is used to calculate the highest point position coordinates and the highest accuracy of the transfer station.The control radius of the accuracy distribution model of the transfer station is studied.(3)The influencing factors of the accuracy of the transfer station in the global measurement space are discussed.The spatial distribution of the accuracy of the station is analyzed from several aspects,such as the number of the common points,the point position accuracy of the common point,the distribution of the position of the common point and the distribution of the position of the point to be measured.(4)The control method of the accuracy of the transfer station in the global measurement space is introduced.The overall adjustment method based on the original observation value and coordinate value is discussed respectively.And the adjustment program is realized by Matlab programming software;Combined with the distribution of point position measurement precision and transformation accuracy,the Leica TM30 total station measuring system is used to simulate the construction of global measurement space.Through the analysis of experimental data processing,the advantages and disadvantages of two kinds of overall adjustment methods are compared.