@InProceedings{ValerianoAlbu:2015:DeMoDi,
               author = "Valeriano, M{\'a}rcio de Morisson and Albuquerque, Paulo Cesar 
                         Gurgel de",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Deriva{\c{c}}{\~a}o de Modelos Digitais de Eleva{\c{c}}{\~a}o 
                         (MDE) em coordenadas geogr{\'a}ficas",
            booktitle = "Anais...",
                 year = "2015",
               editor = "Gherardi, Douglas Francisco Marcolino and Arag{\~a}o, Luiz 
                         Eduardo Oliveira e Cruz de",
                pages = "1860--1867",
         organization = "Simp{\'o}sio Brasileiro de Sensoriamento Remoto, 17. (SBSR)",
            publisher = "Instituto Nacional de Pesquisas Espaciais (INPE)",
              address = "S{\~a}o Jos{\'e} dos Campos",
             abstract = "This paper focuses conceptually-based cares to de observed when 
                         dealing with geographical coordinates in the derivation of 
                         broad-coverage Digital Elevation Models (DEM), as SRTM, GDEM/ASTER 
                         and the upcoming surveys. The derivation of slope was tested under 
                         two conditions for computing the horizontal component. In the more 
                         rigorous approach, DEM pixels are taken as rectangles with 
                         dimensions determined by the geodetic relation between coordinates 
                         units and the corresponding terrain (horizontal) distance, in the 
                         latitudinal and longitudinal directions. In the test area (32º S), 
                         the resulting pixel dimensions of a square spacing grid of 1 were 
                         approximately 25m and 31m (x and y), a distortion of 25% from the 
                         implicit relation assumed in the direct application of derivation 
                         filters. The incoming errors from the simple (square) approach, 
                         with deviances up to 4º, reflected an underestimation of slope 
                         angles prevailing in the E and W slopes. Proportionally to the 
                         results from the rectangular approach, errors were mostly 
                         distributed up to 25%, with outliers above 50%. These errors were 
                         correlated to steepness, and enough to alter the slope-interval 
                         class (towards gentler relief) of 8,6% of the tested area. Of the 
                         E and W oriented slopes, 13% of the area was misclassified. 
                         Regarding the relief classes themselves, the proportional area of 
                         misclassification increased according to the steepness of the 
                         relief, with 64% of steepest areas (slopes from 20% to 45%) 
                         falling into the preceding slope class (8% to 20%).",
  conference-location = "Jo{\~a}o Pessoa",
      conference-year = "25-29 abr. 2015",
                 isbn = "978-85-17-0076-8",
                label = "369",
             language = "pt",
         organisation = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                  ibi = "8JMKD3MGP6W34M/3JM49D3",
                  url = "http://urlib.net/ibi/8JMKD3MGP6W34M/3JM49D3",
           targetfile = "p0369.pdf",
                 type = "Geoprocessamento e aplica{\c{c}}{\~o}es",
        urlaccessdate = "27 abr. 2024"
}