The Research Of Three-dimensional Laser Scanning Techniques In 3DGIS Modeling And Visualization

GIS is a kind of basic computer platform which used to collect, storage, manage, analyse, display and apply geographic information, whose main function is data input, management and output. Three-dimensional information technology is an important part of GIS, and a hot research field in the current geographic information. Three-dimensional GIS attempts to understand and express ground features, geographic phenomenas and spatial relations from the angle of three-dimensional space directly.Three-dimensional modeling and visualization technology helps users to understand the spatial data relationship and analysis results intuitively. Visualization is the combination of scientific computing and graphics image technology, which involves multiple cross-disciplinary areas. The basic ideas of visualization is to express data using graphic image.An important research content of GIS is to generate three-dimensional perspective drawings of landscapes, to imitate true environments based on the spatial data, and to display geographic information, analyse spatial data. It is also a major technology to establish the "Digital Earth".This article mainly descripts the problems of processing three-dimensional data, data modeling, and data visualization; analyses the advantages and disadvantages of domestic and foreign mainstream three-dimensional GIS software platform.This introduces the Terrestrial Laser Scanning Techniques, contrasts the traditional measuring technology, draws the advantages of application in surveying and mapping, and presentates the application methods in the three-dimensional data modeling. Meanwhile, it discusses the key issues of three-dimensional laser scanning data processing, including the point cloud data processing and stitching method, three-dimensional laser scanning system error influence. Using the follow-up processing software Cyclone to conduct a series of processing on the actual three-dimensional laser scanning data to obtain the modeling data, model and output the data, finally achieve visualization. And based on the three-dimensional visualization data of the Yellow River xiaolangdi water conservancy hub project, preliminary established the Yellow River xiaolangdi online system using VS2008 platform and JavaScript language, finally realized the three-dimensional GIS network sharing.