Abstract:

The extraction of slope from Grid DEM is generally through difference algorithms using neighbor analysis (NA), its error is subject to 3 factors: DEM error，DEM data structure and slope algorithms. This study will focusing on slope noise error that is caused by DEM noise error component, this paper will deduct the slope error model on the condition of interpolating points to grid DEM, and evaluated how noise error autocorrelation caused by interpolate influence the slope accuracy. In order to find the rules of noise error autocorrelation influences to slope accuracy, we select case experiment that was taken 5 slope difference algorithms and 4 interpolation methods as example, the experimental results show that slope accuracy can be significantly influenced by DEM noise error autocorrelation, and will be slightly changed with the different interpolation methods and slope algorithms.

Key words: DEM, Slope, Accuracy, Spatial autocorrelation