Cartografia

Anais XV Simpósio Brasileiro de Sensoriamento Remoto - SBSR, Curitiba, PR, Brasil, 30 de abril a 05 de maio de 2011, INPE p.8880

Comparação entre métodos para geração de modelos digitais de elevação a partir de dados cartográficos
Moisés Pereira Galvão Salgado1
Antônio Roberto Formaggio2
Bernardo Friedrich Theodor Rudorff2
1, 2

Instituto Nacional de Pesquisas Espaciais - INPE
Caixa Postal 515 - 12227-010 - São José dos Campos - SP, Brasil
{salgado, formag, bernardo}@dsr.inpe.br
Abstract. This paper aims to compare different methods to generate digital elevation models (DEM) of a catchment area, from digitized cartographic data. The selected study area was the Rocinha microbasin, located at south of Taubaté city, São Paulo state, Brazil. Eight different methods of interpolation were compared both by correlation analysis with the original data and by techniques of visual analysis. Correlation analysis allowed estimating the proportion of changes in the original elevation values caused by different interpolation methods, and the highest ratio found was 0.09% from the Kriging method. Despite the small proportions of changes in altitude values in cells intercepted by altimetric data, the cells that were not intercepted (located in the spaces between contour lines) showed considerable differences between the interpolation methods. The visual analysis of images generated using shaded relief, slope variation and bipolar differentiation technique allowed us to distinguish some artifacts produced by the different interpolation methods. We observed that the prevalence of artifacts occurs mainly in the plain areas, due to lower density of elevation data used in the interpolation process.
We conclude that the selection of the interpolation method should consider the final application of DEM.
Conventional methods of interpolation can disadvantage hydrological studies or applications that aim to calculate topographic variables from the DEM.