Investigating the effects of DEM error in scaling analysis.

Abstract

Digital elevation models (DEMs) are prone to error that, as they can never be entirely eliminated, must be managed effectively. Thus, it is important to understand the nature of error and their sources, especially in the context of the intended use of a DEM. This paper investigates the effects that can be expected when common DEM errors propagate through a scaling analysis. The errors investigated include those associated with perturbation of camera exterior orientation parameters, focal length, and DEM image coordinates, which were simulated numerically. The role of detrending was also investigated. Scaling analysis, by way of the fractal dimension, using a new two-dimensional approach was carried out on a variety of surfaces before and after the introduction of error and the application of detrending. The results reveal some serious procedural implications on scaling analysis and cast doubt on the authenticity of some scaling analysis results in the absence of robust quality assessment and of independent supporting evidence.