The Research On Combined Adjustment Methods Associate With Gravity Field Model And Software Development

In recent years, GPS has been developed continuously in surveying and mapping works in our country, and the range of its application is expanding. With the GPS surveying has become a basic means of surveying, the control network in engineering surveying consists of GPS network, Total Station Plane network, Elevation network, and the Terrestrial network in this thesis is the Total Station Plane network. In engineering surveying, Terrestrial network and GPS network is always joint designed because of the importance of GPS for the design and improvement of Terrestrial control network. The processing of GPS data and terrestrial surveying data is a very important part in the late work of joint network, and it can determine the implementation of the program and the accuracy of the results. This thesis is mainly about the combined adjustment problems of the GPS data and terrestrial surveying data in joint network.In many surveying programs, GPS data is the original data of Terrestrial network, and GPS data can influent the accuracy of the Terrestrial network, so the combined adjustment is always used in the joint network to get a set of more accurate data.This thesis puts more emphasis on the discussing of the theoretical models of combined adjustment, and an application program based on one kind of the theoretical models is coded. Many coordinate systems and the transformation between each other about GPS and Total Station surveying is listed in this thesis. Three kinds of combined adjustment models is described in detail in this thesis:adjustment model on the ellipsoid, adjustment model on the Gaussian surface, adjustment model in the spatial three-dimensional coordinate system.Based on the theory of combined adjustment in the WGS-84 coordinate system, a program on data processing of combined adjustment in the spatial three-dimensional coordinate system of GPS and terrestrial surveying is coded on the Eclipse platform using Java language. The theoretical basis of the program is the mathematical model of transforming the surveying data to baselines in the station coordinate system and the spatial three-dimensional coordinate system, and carrying out combined adjustment with GPS baselines. Through processing the Tunnel Trough Surveying network using this program and comparing the processing results with the terrestrial network adjustment, the utility and capability of the program is verified.