The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Publications Copernicus
Articles | Volume XL-5/W3
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XL-5/W3, 73–77, 2013
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XL-5/W3, 73–77, 2013
07 Jan 2014
07 Jan 2014


V. Casella and B. Padova V. Casella and B. Padova
  • Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy

Keywords: DEM/DTM, Accuracy, Error, Surface

Abstract. Digital Elevation Models (DEMs) play a key role in hydrological risk prevention and mitigation: hydraulic numeric simulations, slope and aspect maps all heavily rely on DEMs. Hydraulic numeric simulations require the used DEM to have a defined accuracy, in order to obtain reliable results. Are the DEM accuracy figures clearly and uniquely defined? The paper focuses on some issues concerning DEM accuracy definition and assessment. Two DEM accuracy definitions can be found in literature: accuracy at the interpolated point and accuracy at the nodes. The former can be estimated by means of randomly distributed check points, while the latter by means of check points coincident with the nodes. The two considered accuracy figures are often treated as equivalent, but they aren't. Given the same DEM, assessing it through one or the other approach gives different results. Our paper performs an in-depth characterization of the two figures and proposes standardization coefficients.