Variogram surface

The Variogram surface operation uses a point map or a raster map as input and calculates a surface of semi-variogram values where each cell (pixel) in the surface represents a directional distance class. The output surface, a raster map with a special kind of georeference, may help you to visualize possible anisotropy of your data and to determine the direction of the anisotropy axis.

Subsequently, you can calculate directional semi-variograms by using the directional method in the Spatial correlation operation. From the output table of Spatial correlation, you can prepare a semi-variogram model with its parameters nugget, sill, range, and you can investigate the range of the variable in the semi-variogram model both in the direction of anisotropy as well as in the direction perpendicular to it. Then, you are ready to perform Anisotropic Kriging.