A Novel Algorithm for Viewshed Based on Digital Elevation Model

Visibility analysis is widely applied to military and project fields, of which viewshed computing is the important factor. This article analyses the advantages and disadvantages of the common algorithms for viewshed computing, and puts forward an improved Xdraw algorithm one to reduce obviously the frequency of access to database aiming at a large scale DEM database. Then the continuous research direction is shown through analysis of this algorithm from correctness and efficiency in practice.