Viewshed Analysis

Viewshed Analysis

A viewshed is an area that is visible from a specific location. Viewshed analyses are a common function of most GIS software. The analysis uses the elevation value of each cell of the DEM to determine visibility to or from a particular cell. The location of this particular cell varies depending on the needs of the analysis. For example, a Viewshed analysis is commonly used to locate communication towers or determining the view from a road. Viewsheds can be calculated using an individual point such as a tower or multiple points such as a line representing a road. When analyzing a line segment, each of the vertices along the line is calculated to determine its visible area. The process can also be reversed. For example, when locating a landfill, the analysis can determine from where the landfill is visible to keep it hidden from view.