Key algorithms study on global terrain visualization

Global terrain visualization is a very challenging subject. In this paper, an algorithm of determining the bounds of the global terrain in the current LOD within the view volume is presented, according to the property of the ellipsoid and the position of the eye point. Picking up 3D Geo-coordinates of the spatial points accurately is the first step toward handling 3D spatial analysis and query, and is also a research difficulty. Visual field analysis, which is widely used in military and communication fields, becomes one of the important research contents. To address these issues, this paper presents more efficient and accurate algorithms for them.