Empirical semivariograms for kriging interpolation

Kriging interpolation is one of the more interesting techniques introduced in the field of surrogate modeling in the last years. This technique has been motivated by the necessity of data interpolation in the geological field in the late sixties. This approach is founded on the availability of the so called "variogram", defined as "a curve representing the degree of continuity of mineralization" [1], that is, the continuity of the interpolating function. Different strategies for the determination of the variogram are here presented, together with an estimate of the degree of accuracy provided by the different alternatives.