Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Digital Elevation Models

  • Leila De Floriani
  • Paola Magillo
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_129

Synonyms

DEMs; Digital Terrain Model (DTM); Digital Surface Model

Definition

A Digital Elevation Model (DEM) represents the 3D shape of a terrain in a digital format. A terrain is mathematically modeled as a function z = f(x, y) which maps each point (x, y) in a planar domain D into an elevation value f(x, y). In this view, the terrain is the graph of function f over D.

In practice, a terrain is known at a finite set of points within D, which may (i) lie at the vertices of a regular grid, (ii) be scattered, or (iii) belong to contour lines (also known as isolines), i.e., the intersections of the terrain surface with a sequence of horizontal planes.

In case (i), the DEM consists of the grid structure plus elevation values at its vertices. This is called a Regular Square Grid(RSG). Within each grid cell, terrain elevation either is defined as constant, or it is modeled by a function, which can be linear (this involves cell decomposition in two triangles), or quadratic (usually,...

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Recommended Reading

  1. 1.
    de Berg M, van Kreveld M, Overmars M, Schwarzkopf O. Computational geometry – algorithms and applications. 2nd ed. Berlin: Springer; 2000.zbMATHGoogle Scholar
  2. 2.
    De Floriani L, Magillo P, Puppo E. Applications of computational geometry to Geographic Information Systems, Chapter 7. In: JR Sack, J Urrutia, editors. Handbook of computational geometry. Elsevier Science; 1999. p. 333–88.Google Scholar
  3. 3.
    De Floriani L, Puppo E. An on-line algorithm for constrained delaunay triangulation. Graph Model Image Process. 1992;54(4):290–300.CrossRefGoogle Scholar
  4. 4.
    Dyn N, Levin D, Rippa S. Data dependent triangulations for piecewise linear interpolation. IMA J Numer Analy. 1990;10(1):137–54.CrossRefMathSciNetzbMATHGoogle Scholar
  5. 5.
    Edelsbrunner H, Tan TS. An upper bound for conforming Delaunay triangulation. Discret Comput Geom. 1993;10(1):197–213.CrossRefMathSciNetzbMATHGoogle Scholar
  6. 6.
    Google Earth home page. http://earth.google.com/
  7. 7.
    Longley PA, Goodchild MF, Maguire DJ, Rhind DW, editors. Geographical information systems. 2nd ed. New York: Wiley; 1999.Google Scholar
  8. 8.
    Microsoft Virtual Earth home page. http://www.microsoft.com/virtualearth/
  9. 9.
    O’Rourke J. Computational geometry in C. 2nd ed. Cambridge: Cambridge University Press; 1998.CrossRefzbMATHGoogle Scholar
  10. 10.
    Peckham RJ, Jordan G, editors. Digital terrain modelling – development and applications in a policy support environment, Lecture notes in geoinformation and cartography. Berlin: Springer; 2007.Google Scholar
  11. 11.
    United States Geological Survey (USGS) home page. http://www.usgs.gov/
  12. 12.
    van Kreveld M. Digital elevation models and TIN algorithms. In: van Kreveld M, Nievergelt J, Roos T, Widmayer P, editors. Algorithmic foundations of geographic information systems, Lecture notes in computer science (tutorials), vol. 1340. Berlin: Springer; 1997. p. 37–78.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.University of GenovaGenoaItaly

Section editors and affiliations

  • Ralf Hartmut Güting
    • 1
  1. 1.Computer ScienceUniversity of HagenHagenGermany