Local error evaluation in DEM using direct sequential simulation (DSS) methodology

Jorge Delgado 1, Amilcar Soares 2, José Luis Pérez 1 and Julia Carvalho 2
1 Dpto. Ingeniería Cartográfica, Geodésica y Fotogrametría.
Escuela Politécnica Superior. Universidad de Jaén
Campus de las Lagunillas, Edif. A-3, 23071 Jaén, Spain
Tel.: + 034 953 212 468; Fax: + 034 953 212 855
jdelgado@ujaen.es; jlperez@ujaen.es
2 Environmental Group of the Center for Modelling Petroleum Reservoirs, CMRP/IST
Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Tel.: + 351 218 417 444; Fax: + 351 218 417 389
asoares@ist.utl.pt; jcarvalho@ist.utl.pt

Abstract
In this paper a methodology for local uncertainty due to the modelling process in a DEM generation is presented. Local uncertainty is a basic aspect to determine the final quality of the DEM and it is crucial in order to establish the capabilities of  use of the model. The proposed methodology is based in the use of geostatistical simulation procedure that provides “possible versions” of the reality from limited terrain information (XYZ terrain points). The simulated model generated by  the geostatistical simulation procedure (direct sequential simulation) allows obtaining the cdf of the elevation in each grid node. Using this cdfs it is possible to calculate the uncertainty of the  DEMs (variance, interquartile range, entropy) through a simple probabilistic analysis and several  realisations of DEM that preserves the statistical characteristics of the measured data (histogram, variogram,…).

Keywords: local error, uncertainty, DEM, direct sequential simulation, geostatistics

In: Caetano, M. and Painho, M. (eds). Proceedings of the 7th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, 5 – 7 July 2006, Lisboa, Instituto Geográfico Português

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