DEM Fractal Simulation And Its Uncertainty Research

Uncertainty is nature a prevalent phenomenon, at the same time also reflect thepeople to know all things of the nature of the limited degree. The uncertainty of theworld to describe the objective world attributes of spatial data of uncertainties. As thebasic part of spatial data, the uncertainty study of DEM has typical significance.The study shows that the surface topography is a fractal nature, so this paper basedof fractal geometry, the self-similarity of fractal characteristics of DEM data field,combining mathematical statistics, statistical methods to research the uncertainty ofDEM， has certain theoretical value.In this paper the surface topography of the fractal characteristics, DEM uncertaintiesand statistical methods based on the analysis of the system, the terrain surface fractalsimulation, combined with the fractal parameters to its further uncertainty are discussed,the main work to have the following several aspects:1) Based on fractal brown surface principle, according to the fractal Brownianmotion simulation principle very similar natural terrain surface, using random midpointdisplacement method, the parameters of the function with fBm describe the surfacebroken degree (H) and terrain ups and downs degrees (σ) of terrain surface fractalsimulation, have different terrain ups and downs and roughness of surface topography,and further discussed in simulation of the uncertainty of the terrain and DEM surfacefractal dimension of mutual relations.2) Based on the surface itself is the surface topography and internal and externalforcing the result of joint action, DEM elevation data field performance in the spacedistribution features is "certain random" phenomenon, and the "certain random"phenomenon completely satisfy fractal rule changes sex, instability, poor correlation,fragmentation, irregular characterized, based on the traditional method of mathematicalstatistics DEM uncertainty research.3) Based on semi-variation function to quantitatively measure DEM elevation datasimulation games of the heterogeneity and space correlation, terrain elevation dataanalysis and field of fractal dimension and elevation data between mutual dependencespace, this paper discusses the elevation data between two points the degree ofuncertainty.4) In the process of this paper to write the last of the paper summarizes and prospect.