Gillings and Wheatley (2020)

Highlight some of major limitations associated with GIS

DEM issues

•  Terrain model reflects modern topography, not ancient landscapes

• E.g. Erosion or human modification could have changed it

Vegetation

• DEMs typically show bare earth

• Ancient woodland, scrub, and seasonal leaf cover would have dramatically reduced visibility in ways that are very hard to model.

Assumption of reciprocity

• Researchers often assume that if A can see B, B can see A.

• This is not automatically true

False precision

• Binary viewsheds look definitive but are not.

• Advocates for:

1. Probabilistic viewsheds that calculate the likelihood of visibility for a given location

2. Fuzzy viewsheds which replace binary visible/invisible results with a gradient of visibility,