Fuzzy Landform Classification with Azimuth-based Fourier Series

The elevation differences between a point of the terrain surface and the points of a circle whose centre is this point may be the base of a Fourier series, where the azimuth (from the examined point to a point of the circle) is the variable of the function.The coefficients of this azimuth-based Fourier series are applicable for the analysis of the elevation models, for example classifying the points of the surface.The described analyses are implemented easy in varied GIS software because the coefficients are calculated by convolution filters.This paper describes equations for calculating fuzzy values of the landform classes from the coefficients of the azimuth-based Fourier series.