why is semivariance used instead of covariance in kriging why are semivariograms used is the semivariogram invertible when are the semivariograms used in kriging what is the difference between covariance and semivariance what is the difference between a semivariogram and a covariogram? which of the following is an example of a semivariogram used instead of a variogram? why are semivariograms used instead of covariance why do we use semivariogram and covariance instead of variance what is the param of a semivariogram why are semivariance weights used in kriging why do we use semivariogram instead of variogram how to do a weight test with the semivariogram why are we using semivariograms instead of covariance how do the semivariograms work? why are semivariograms used instead of covariance? which params are used in an ordinary kriging method? what is the difference between semivariance and a variogram in ordinary kriging why is semivariance used as a weight in kriging why do they use covariance instead of semivariance