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Approximation theory applied to DEM vertical accuracy assessment / X. Liu in Transactions in GIS, vol 16 n° 3 (June 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 3 (June 2012) . - pp 397 - 410 Titre : Approximation theory applied to DEM vertical accuracy assessment Type de document : Article/Communication Auteurs : X. Liu, Auteur ; P. Hu, Auteur ; H. Hu, Auteur ; J. Sherda, Auteur Année de publication : 2012 Article en page(s) : pp 397 - 410 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] approximation [Termes IGN] estimation statistique [Termes IGN] interpolation linéaire [Termes IGN] modèle numérique de surface [Termes IGN] précision altimétrique [Termes IGN] précision du positionnement Résumé : (Auteur) Existing research on DEM vertical accuracy assessment uses mainly statistical methods, in particular variance and RMSE which are both based on the error propagation theory in statistics. This article demonstrates that error propagation theory is not applicable because the critical assumption behind it cannot be satisfied. In fact, the non-random, non-normal, and non-stationary nature of DEM error makes it very challenging to apply statistical methods. This article presents approximation theory as a new methodology and illustrates its application to DEMs created by linear interpolation using contour lines as the source data. Applying approximation theory, a DEM's accuracy is determined by the largest error of any point (not samples) in the entire study area. The error at a point is bounded by max(|?mode|+M2h2/8) where |?node| is the error in the source data used to interpolate the point, M2 is the maximum norm of the second-order derivative which can be interpreted as curvature, and h is the length of the line on which linear interpolation is conducted. The article explains how to compute each term and illustrates how this new methodology based on approximation theory effectively facilitates DEM accuracy assessment and quality control. Numéro de notice : A2012-283 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01343.x Date de publication en ligne : 28/05/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01343.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31729 [article]