| dc.description.abstract | Several important applications of geographic information systems (GIS) require visibility computation, such as, the line-of-sight communication, the optimal placement of a radial tower or a watchtower, finding the path with certain visibility properties (scenic or hidden paths) and so on. Thus, a better visibility computation algorithm makes the applications more efficient. The goal of our research is to study the visibility computation technique and implement the algorithm for several related applications.
In this study, we proposed an improved visibility computation algorithm which is based on the triangulated irregular networks. We use intersection test module instead of the general projection method to achieve the same results; moreover, we use specific angles to narrow the test range to improve performance. By the proposed methods, we can reduce the computation of the algorithm to obtain better performance.
The proposed algorithm is roughly divided into three parts: the spatial analyst, radial sort, and visibility computation. First, the spatial analyst performs the neighborhood and zone analysis for visibility computation. Second, the radial sort step decides the processing sequence. Finally, the visibility computation step calculates the visibility information.
The visibility information obtained form our visibility computation algorithm can conform to the properties of line-of-sight. Therefore, the visibility information can solve the line-of-sight computation problems on TINs for lots of applications. | en_US |