Digital analysis of viewshed inclusion and topographic features on digital elevation models

This short paper formally defines and documents how pixels of digital elevation models dominate each other in visibility with respect to their topographic characteristics. Two pixels are defined as mutually visible if a straight line that connects these two pixels can be constructed without intersecting any other parts of the topographic surface. Dominance occurs when all visible pixels from a viewing pixel are also visible from another viewing pixel. Pixels of various topographic characteristics examined here include pixels classified as peaks and pits, and those pixels on ravines and ridges. Visibility dominance among pixels of digital elevation models may be used to enhance and speed up visibility analyses such as watchtower siting or viewshed assessment. 11 refs.