The Research On Combined Adjustment Methods And Software Development Of GPS And Terrestrial Surveying Data

In recent years, with the rapid development of GPS positioning technology, application of GPS technology to establish and transform a variety of land and engineering surveying and mapping control network has aroused world attention. This thesis presents the discussion and investigation on the function model and stochastic model established in the combined adjustment of GPS and terrestrial surveying data.First, it is illustrated that four kinds of commonly used mathematical model and their fundamentals for GPS and terrestrial surveying data combined adjustment. These mathematical models include:The mathematical model of adjustment in the reference center rectangular space coordinates, the mathematical model of adjustment in the reference center geodetic coordinates and the two modes'mathematical model of adjustment in the two-dimensional Cartesian coordinates. These four kinds of combined adjustment of the mathematical model are compared and analyzed. Summarize the advantages and disadvantages of various mathematical models of the combined adjustment and their application.Then, the methods of weight determination of different observations were studied. By comparing the results of two combined adjustment of weight determination with experience and weight determination with Helmert variance component estimation, obtained that using different methods to determine weight, the results of the combined adjustment will be affected. In order to obtain the optimal parameter estimates and reasonable accuracy evaluation should use Helmert variance component estimation method to deal with the combined adjustment.Finally, according to the derived algorithms and conclusions, the software, GPS and terrestrial surveying data combined adjustment (UnionAdj) is developed utilizing Visual C++ tool to meet the needs in various projects.