Figure 2.
The left chart plots error versus theta in metres. Error decreases from about 1.2 to a minimum near 0.95 at theta about 1.54, then increases again. The right chart shows a similar trend, with minimum error near 0.96 at theta about 2.91. Both curves are U-shaped, and the minimum points are marked with dots and vertical dashed lines.Variation of error with respect to estimated using (a) autocovariance function fitting () and (b) semivariogram method ()