The Development Of AGRS Surface Visualization System

The content of the paper relates to acknowledge in some kinds of subjects, suchas Surface Visualization, Computer Graphics, Man-machine Conversion Technology,Software Engineering, Component System Design and Aviation Exploration. Etc.During the process of development, the first thing which I carried out is to studythe constitution algorithm of the 3D Visualization and the current situation of theresearch on the subject. At the same time the paper lists the focus problems on thesubject. Secondly, the author comprehended the advantage and disadvantage of thenational and international 3D GIS Software, and collected the practical problems ofthose types of 3D GIS Software. At the basis of the research on the constitutionalgorithm of the DTM and the feature of the 3D GIS Software, the author establishedthe goal of the development activity. The paper comply the principles as followsduring the process of the development of the AGRS Surface Visualization System:Module, Object oriented, Friendly interface, Refinement and easy to operate.During the course of the development, the author exerts the ArcGIS Enginecomponent base and VB.NET to develop the visualization system which isindependent from the ArcGIS Desktop. The modules include model constitution,visualization and analysis in particular. In these modules, the function of the modelconstitution module is to constitute point feature class from text file, the constitutionof the TIN (Irregular Triangulated Network) and ESRI GRID, the conversion ofseveral common surface model formats and the transformation between TIN andESRI GRID. The function of the module of visualization is to display, browse, shrinkand magnify the data, install the sunshine model, transform the windows and controlthe layers etc. The function of the analysis module is the creation of contour linefeature class from the TIN and ESRI GRID, the constitution of the slope and aspectdata from the TIN and ESRI GRID, and the achievement of inclusive information inthe multiple surface model layers.On the basis of the software designing route, at the beginning of the developmentactivity the author studied the basic theory of the surface model. Furthermore, theauthor examined the constitution algorithms of the TIN and ESRI GRID. By utilizingthe ArcGIS Engine component base the paper carries out the function to constitute theTIN and ESRI GRID, and the derivation of contour data from the DTM. At the sametime the paper provides the function to constitute the DTM which is special for thedata in the project, the method detracts the frequency of flat triangles, narrow trianglesand empty data. After the research on the advantages and disadvantages of the TINand ESRI GRID, the author realizes the function of merging the superiority of twotypes of DTM which is to transform between each other.The paper inspected the data structure of three types of DTM, such as GeoStar,ASCII GRID and ESRI GRID. On the basis of the research on the formats and datastructure of the three types of DTM, the paper provides the function of the conversionamong those types of DTM. The paper exerts two methods to investigate the inclusiveimplication of multiple DTM layers, which include the installation of transparency ofthe DTM surface and multiple profiles which breaks the limitation of the singleprofile function in the primitive GIS software.