GeoInformatica

, Volume 15, Issue 2, pp 381–397

Efficient viewshed computation on terrain in external memory

  • Marcus V. A. Andrade
  • Salles V. G. Magalhães
  • Mirella A. Magalhães
  • W. Randolph Franklin
  • Barbara M. Cutler
Article

DOI: 10.1007/s10707-009-0100-9

Cite this article as:
Andrade, M.V.A., Magalhães, S.V.G., Magalhães, M.A. et al. Geoinformatica (2011) 15: 381. doi:10.1007/s10707-009-0100-9

Abstract

The recent availability of detailed geographic data permits terrain applications to process large areas at high resolution. However the required massive data processing presents significant challenges, demanding algorithms optimized for both data movement and computation. One such application is viewshed computation, that is, to determine all the points visible from a given point p. In this paper, we present an efficient algorithm to compute viewsheds on terrain stored in external memory. In the usual case where the observer’s radius of interest is smaller than the terrain size, the algorithm complexity is θ(scan(n2)) where n2 is the number of points in an n × n DEM and scan(n2) is the minimum number of I/O operations required to read n2 contiguous items from external memory. This is much faster than existing published algorithms.

Keywords

GIS External memory processing Viewshed Visibility maps 

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Marcus V. A. Andrade
    • 1
    • 2
  • Salles V. G. Magalhães
    • 1
  • Mirella A. Magalhães
    • 1
  • W. Randolph Franklin
    • 2
  • Barbara M. Cutler
    • 3
  1. 1.DPIUniversidade Federal de ViçosaViçosaBrasil
  2. 2.ECSE Dept.Rensselaer Polytechnic InstituteTroyUSA
  3. 3.CS Dept.Rensselaer Polytechnic InstituteTroyUSA