Landscape Archaeology

Welcome visibility index algorithm, a.k.a. total viewshed, now available in QGIS Visibility analysis plugin. This metric informs us on the size of the visual field for any location across a given terrain, normally each pixel in a gridded digital elevation model (DEM). At first, visibility index resembles other terrain indices... [Read More]

So, you have your data, you’ve installed a GIS program … and there we go: slope gradient – check, solar exposition – check, water drainage – check, visibility range – check … [Read More]

Viewshed analysis produces a model of visible areas from a chosen point, given a 2.5 or 3D elevation model. Most often, we model full range visibility, in all directions from an observer point, but such models may not satisfy all uses. For instance, we are sometimes interested in a scene... [Read More]

Viewshed analysis denotes field of vision modelling in GIS jargon. The term is quite awkwardly borrowing its suffix from watershed, even if there is nothing being “shed”. Anyway, the term viewshed has become commonplace in GIS terminology and is here to stay. [Read More]

Ambient occlusion is a concept developed in 3D modelling and visualisation which is used to evaluate the exposition to the ambient light of each model element. The idea is to simulate the diffuse, scattered light that bounces off various surfaces. Such light may not have an identifiable source, as for... [Read More]