Viewshed analysis, a form of visibility analysis that identifies visibility between points in a landscape, emerged as a geographic field several decades ago. Recent advances in software and computing power enabled viewshed analysis to become a common form of geographical analysis, and it is now a standard tool in many geographic [Page 3017]information systems, enabling viewshed analysis to be used in a range of fields. The following entry discusses the techniques used to calculate and analyze viewsheds as well as the applications of viewshed analysis.

Figure 1 Sample viewshed

Source: Author.

Viewshed analysis is typically conducted as a raster-based operation in a GIS. It begins with the calculation of a viewshed, a two-dimensional (2D) projection of a view, using one of many algorithms (see DeFloriani & Magillo, 2003). ...