Hi..
In the Mapwindow version 4.8.6, the linear model is implemented.. I don't include this linear variogram in the geostatistical tool.
The automatic kriging is not "really" possible, there are infinite solutions for a variogram taking into account parameter like number of lags, size of lag,
the anisotropy, type of theoretical model (i.e Spherical, linear, circular). When one of these parameters changes, there is a new solution..
By default all Geostatistical packages generate a default initial solution, but it doesn't mean that it is the best solution.
For obtaining the best theoretical model is needed to fix the empirical semivariances or Covariance to selected model. There are some
algorithms used to determine the best model, WLS or OLS,
(Cressie, N., 1985. Fitting variogram models by weighted least squares. Math. Geol. 17, 563–586.) In this article you can find the most common method to fit a variagram..
(Leastsquares ftting from the variogram cloud, muller,1998)
In the Geostatistical Tool is used an OLS to get the best model..
Carlos
