Algoritmo eficiente para cálculo de mapas de visibilidade em terrenos armazenados em memória externa

• Autor(a) principal: Magalhães, Mirella Antunes de
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2606
• topic: Mapas de visibilidade; Modelo digital de terrenos; Processamento externo; Sistema de informação geográfica; Visibility maps; Digital terrain model; External processing; Geographic information system; CNPQ::CIENCIAS EXATAS E DA TERRA::CIENCIA DA COMPUTACAO

As more detailed terrain data become available, many terrain applications must process large geographic areas at higher resolutions. The massive data processing involved in such applications presents significant challenges to GIS and requires algorithms that are optimized for both data transfer and for computation. One of these applications is the viewshed computation, that is, to determine all visible points from a given point p. In this work, we present an study and, as a result, an efficient algorithm to compute the viewshed on terrains stored in external memory. The algorithm complexity is a function of the number of I/O operations required to calculate the viewshed and, as shown by the results, our algorithm is more efficient than other algorithms described in the literature.