Key Technologies of a WebGIS-Based 3D Visualization System for the Moon

Data of the moon in a large amount have been recorded in the Chang'E lunar exploration project. To meet the public need of better understanding the moon through the Web, the Ground Application System proposed solutions of 3-dimensional visualization systems for the moon based on the WebGIS. In this paper we first introduce the status of the development of visualization systems for the moon in China and abroad. We then analyze technologies and platform software components of developing clients and servers in the WebGIS. We choose the Javascript as the technology to develop a client, and choose the Weblogic as a platform to develop a server. We also use the ArcGIS Server and the MGIS GIS software of domestic origin as the development platforms in a design of a 3-dimensional visualization system for the moon. The paper focuses on key technologies of 3-dimensional GIS visualization, such as techniques of modeling 3-dimensional lunar data and algorithms of organizing/scheduling/rendering 3-dimensional scene graphs. A system according to our design organizes DEM and DOM lunar data with the pyramid data structure, and manages vector data (e.g. terrain names) hierarchically. It assigns two queues to accept user requests and send processed data, respectively. This ensures fluent and fast display of 3-dimensional scenes at a front end. The paper finally summarizes relevant technologies and outlines of the solution to support building 3-dimensional moon-visualization systems in China.