Study And Application Of Visualization Methods Of Land Gravity Surveying

With the fast development of high techniques like computer, digitization and visualization of surveying and mapping is emerging all over the world. New terms, like digital Earth, digital China and digital city have become well-known. However, in the field of geodesy especially physical geodesy, the presentation of the research is only in the stage of numerical demonstration and service, which lacks intuitive and easy-to-understand visualization. Therefore, the comprehension and acceptance of geodesy are confined. In this thesis, an example is given on the study and development of a software system of field terrain matching and automatic arranging points of land gravity surveying, by which the visualization techniques available to geodesy are investigated. The main work of this thesis includes:1. The mathematic model of automatic arranging points using height data is established based on principles of land gravity surveying and design strategy of arranging points.2. Aiming at the development of the system of field terrain matching and automatic arranging points of land gravity surveying, software requirements analysis and system detailed design are implemented and reusable classes are extracted using the software engineering modeling tool, UML, which resolves the key problems encountered in software documentation and software maintenance.3. Implementation methods as well as applications are discussed of classical visualization techniques which include usage of the graphics library OpenGL, 2-D rendering of terrain, 3-D display, BillBoard, Alpha and computer animation technique based on MFC library.4. The visualization system of automatic arranging points of land gravity surveying and field terrain matching is designed and developed, which has capabilities of 2-D terrain processing, 3-D visualization, terrain category matching, location display of gravity points, human-computer interface and location report generation of gravimetric points for different requirements of surveying accuracy. The system overcomes the difficulty of overtopping average height limitation caused by manual design of locations of arranging points. By enhancing the intuitional understanding of arranging points of field gravimetry, the purpose of properly...