First experiments in viewshed uncertainty : simulating fuzzy viewsheds
Peter Fischer · Photogrammetric Engineering & Remote Sensing · 1992
Calculation of the viewshed from a digital elevation model (OEM) is a common capability of a GIS packages. Two mistaken assumptions are made, however: first, that the OEM is accurate, and second that the viewshed is a Boolean phenomenon. The inaccuracy of the OEM data is acknowledged in reporting of the root-mean-squared error. The mistake of the Boolean viewshed is recognizable in the real-world experience of most individuals. In this paper multiple realizations of an error simulation algorithm are used to generate multiple Boolean viewsheds which are then cumulated to yield an image of the viewshed with all the properties of a fuzzy set, Le., a fuzzy viewshed. Alternative parameterizations of the basic algorithm are presented, and the differences are explored.