Characteric mean and dispersion in surface orientations for a zone

Abstract
Descriptive statistics for mean and dispersion measures of surface orientations are important in characterizing a zone of such diversity that more than one observation is required to represent it adequately. The derivation of such statistics related to aspect is problematic because of the circular scale used to measure aspect and the hemispherical scale for both slope and aspect. Two techniques are presented for computing the mean and dispersion measures of aspect and a bi-directional surface orientation. The relevant directional statistics are briefly presented with appropriate examples.