2026-07-23T07:03:04Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:14769 2024-03-06T10:54:52Z ddc:004 open_access

Terrain Prickliness: Theoretical Grounds for High Complexity Viewsheds Acharyya, Ankush Jallu, Ramesh K. Löffler, Maarten Meijer, Gert G.T. Saumell, Maria Silveira, Rodrigo I. Staals, Frank Digital elevation model Triangulated irregular network Viewshed complexity An important task in terrain analysis is computing viewsheds. A viewshed is the union of all the parts of the terrain that are visible from a given viewpoint or set of viewpoints. The complexity of a viewshed can vary significantly depending on the terrain topography and the viewpoint position. In this work we study a new topographic attribute, the prickliness, that measures the number of local maxima in a terrain from all possible angles of view. We show that the prickliness effectively captures the potential of terrains to have high complexity viewsheds. We present near-optimal algorithms to compute it for TIN terrains, and efficient approximate algorithms for raster DEMs. We validate the usefulness of the prickliness attribute with experiments in a large set of real terrains. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Ankush Acharyya and Ramesh K. Jallu and Maarten Löffler and Gert G.T. Meijer and Maria Saumell and Rodrigo I. Silveira and Frank Staals 2021 Is Part Of LIPIcs, Volume 208, 11th International Conference on Geographic Information Science (GIScience 2021) - Part II InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.GIScience.2021.II.10 urn:nbn:de:0030-drops-147697 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.GIScience.2021.II.10 eng https://creativecommons.org/licenses/by/4.0/legalcode