Efficient Viewshed Analysis as QGIS Plugin

Topographic relationships between two point locations are their intervisibility. Intervisibility is a spatial analysis of the source point (observer) which may be on some height; to destination point (target) and all intermediate points residing along this line. This process of source point to destination point intervisibility along the line could be extended to viewshed analysis by calling the function recursively from the source point to all boundary points of a circle over DEM image. Visibility analysis is of great importance in many fields such as sensor deployment, decision for placement of mobile tower for maximum coverage, military operation planning, gaming, fire monitoring tower in the forest etc. This paper proposes a slope and stationary point (local maxima/minima) based efficient algorithm and development of a plug-in utility in QGIS for viewshed analysis and its computation performance comparison with other open source software's similar utility application.