New Technologies Of Large Scale Topographic Map In Qingdao

Forming large scale topographic maps by integrating CORS system integration, geoid refinement and aerial topographic method and other advanced methods constitute the systems approach for urban large scale mapping. Building basic geographic information database construction and network-based basic geographic information management system is the development trend of digital city. In the past, large scale topographic map was mainly formed by traditional method, which is far from meeting the needs of social and economic development.Traditional large scale topographic mapping is usually curried out by laying a large number of control points in field surveys. This approach has many drawbacks, for example, it takes a large amount of field work, it is complex to process data in the office work, and it requires a lot of manpower and material resources. In addition, this approach need the must-have process such as laying traverse and sectional survey points, which needs a long time and large amount of manpower and material resources and has a slow speed of renewing. This approach cannot meet the needs of rapid social and economic development. Therefore, it is necessary to explore and practice new methods, technologies and processes to improve work efficiency and quality. The standard system for establishing databases of cities' 1:5000 scale Digital Line Graphic (DLG), Digital Orthophoto Map (DOM) and Digital Elevation Model (DEM) (referred to as 3D) is imperfect, and they still need be refined and improved. Due to some cities'special characteristics, it is necessary to increase some graphic symbols and codes to meet requirements in practical works. At present, with the accelerated pace of as digital cities'construction, building a graphical information platform has become the most important work. It is urgent to research and establish a web-based and distributed-stored platform framework to provide real-time data-updating services, to undertake and realize a web-based sharing system for government management and social-running to enhance the level of city information.In 2009 a 1:5000 scale map surveying project was started in Qingdao, which required to complete Qingdao 1:5000 large scale topographic map based on exploration and establishment of new mapping technology system. This project introduces the whole process of 1:5000 scale surveying of Qingdao, including control measurements, field mapping, data processing, database building, and management information systems development. Main achievements are as follows:â‘ Create a new method of Qingdao field single point flow station directly acquiring high-precision three-dimensional coordinates:This project practiced the integration of the 5cm accuracy quasi-geoid covering the Qingdao area and 3cm accuracy quasi-geoid covering the main city of Qingdao. This product was successfully integrated to the Qingdao continuously operating reference station (CORS) system in order to publish the real-time correction parameters of coordinates and heights. By doing this, a single moving GPS station can be used to obtain the high-accuracy three-dimensional coordinates. This innovative approach has changed the traditional survey method of executing level-by-level control network and improved the speed and accuracy of large scale topographic map.â‘¡Complete Qingdao large scale topographic map 3D database construction:After field surveying, the project revised and improved database building standard in accordance of relative technology standards of the State and province. This project firstly established a complete and expandable database standard including 1:5000 scale DLG, DOM and DEM, which laid a solid foundation for unifying and standardizing the city GIS data.â‘¢Develop large scale geographic information management system of Qingdao:Based on 3D database,a geographical information management system was developed based on ArcGIS Engine, ArcGIS Server, Oracle, etc. This system includes three subsystems, i.e.: data storage subsystem, data management application subsystems, and system configuration maintenance subsystem. The system built a GIS-based data platform framework of digital Qingdao, achieving the network sharing of geographical data, which provides secondary development interface for users and provides the basic data real-time updating service.After two years'research, the project was completed successfully. 1:5000 scale maps and its management system completed in this project have filled the blank of Qingdao and have played an important role in the urban management, construction and development. The study results were successfully used on the developing design of Qingdao city, drilling wells, and constructing the new airport of Qingdao. Through this research, a complete set of new large scale topographic map technology system has been established, which will play an important role in the building of Blue Economic Zone of Shandong Peninsula.