INDAL 1995-96: Spatial Statistics

The quality or the concentration of (Al$_2$O$_3$, SiO$_2$) of the Radhanagari bauxite deposit was predicted via kriging. INDAL was using a custom-built FORTRAN based software for kriging, which was yielding unacceptably high prediction error. Since the software offered only a limited choice in the variogram model selection, MATHEMATICA programs doing Exploratory Data Analysis, suggesting an appropriate variogram model, were written first. It turned out that the wave-effect variogram model, as opposed to the spherical one, suggested by the software, fitted the data better. Since the software did not have a provision for fitting the wave-effect model, C programs were written fitting the wave-effect model and also for the eventual kriging. Thus although the prediction error was reduced considerably, it was still high (due to the noise in the data) for their purpose, and was reported accordingly.