2004 UC Proceedings Abstract
 The Effect of Grid Cell Size on Major Terrain Derivatives Track: Water Resources Author(s): Stefan Kienzle This paper examines the quality of DEMs derived from the interpolation of photogrammetrically derived elevation points. DEMs with grid cell sizes ranging from 100 to 5 m were interpolated from 100 m regularly spaced elevation points and many surface-specific point elevations using the ANUDEM interpolation method. In order to identify the grid resolution that matches the information content of the source data, three approaches were applied: density analysis of point elevations, an analysis of cumulative frequency distributions using the Kolmogorov-Smirnov test and the root mean square slope measure. Results reveal that the optimum grid cell size is between 5 and 20 m, depending on terrain complexity and terrain derivative. Terrain variables based on 100 m regularly sampled elevation points are compared to an independent high-resolution DEM used as a benchmark. Correlation analysis, root mean square errors, and relative root mean square errors further quantify the quality of terrain derivatives. Stefan Kienzle University of Lethbridge Geography 4401 University Drive Lethbridge T1K 3M4 CA Phone: 403 - 380 1875 E-mail: stefan.kienzle@uleth.ca |
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