Journal cover Journal topic
Proceedings of the ICA
Journal topic
Articles | Volume 4
Proc. Int. Cartogr. Assoc., 4, 11, 2021
Proc. Int. Cartogr. Assoc., 4, 11, 2021

  03 Dec 2021

03 Dec 2021

Horizontal accuracy assessment of a novel algorithm for approximate a surface to a DEM

Domingo Barrera1,2, María José Ibáñez1, Salah Eddargani1,3, Rocio Romero4, Francisco J. Ariza-López5, and Juan F. Reinoso-Gordo6 Domingo Barrera et al.
  • 1Department of Applied Mathematics, University of Granada, Spain
  • 2IMAG – Institute of Mathematics, Granada, Spain
  • 3University Hassan First, MISI Laboratory, Morocco
  • 4Department of Computer Science and Artificial Intelligence, University of Granada, Spain
  • 5Department of Cartographic, Geodesic and Photogrammetry Engineering, University of Jaén, Spain
  • 6Department of Architectural and Engineering Graphic Expression, University of Granada, Spain

Keywords: Spline, Bernstein basis, control points, Bézier ordinates, tensor product, resample, horizontal accuracy, DEM

Abstract. This study evaluates the horizontal positional accuracy of a new algorithm that defines a surface that approximates DEM data by means of a spline function. This algorithm allows evaluating the surface at any point in its definition domain and allows analytically estimating other parameters of interest, such as slopes, orientations, etc. To evaluate the accuracy achieved with the algorithm, we use a reference DEM 2 m × 2 m (DEMref) from which the derived DEMs are obtained at 4 m × 4 m, 8 m × 8 m and 16 m × 16 m (DEMder). For each DEMder its spline approximant is calculated, which is evaluated at the same points occupied by the DEMref cells, getting a resampled DEM 2 × 2 m (DEMrem). The horizontal accuracy is obtained by computing the area amongs the homologous contour lines derived from DEMref and DEMrem, respectively. It has been observed that the planimetric errors of the proposed algorithm are very small, even in flat areas, where you could expect major differences. Therefore, this algorithm could be used when an evaluation of the horizontal positional accuracy of a DEM product at lower resolution (DEMpro) and a different producing source than the higher resolution DEMref is wanted.

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