Universal Kriging
Universal Kriging can be seen as a point interpolation, which requires a point map as input and which returns a raster map with estimations and optionally an error map. Universal Kriging is a variant of the Ordinary Kriging operation: Universal Kriging is Kriging with a local trend. The local trend or drift is a continuous and slowly varying trend surface on top of which the variation to be interpolated is superimposed. The local trend is recomputed for each output pixel and the operation is therefore more similar to the Moving Surface operation than to the Trend Surface operation.
Before Universal Kriging, you should perform the Spatial Correlation operation, and determine a semi-variogram model in a graph window (Graph window : Add semi-variogram model).