3-D interpolation of subsurface temperature data with measurement error using kriging

A computer program called jk3d for 3-D ordinary kriging interpolation of scattered data has been developed. A specific feature of the code is that differences of the quality of the measured data are taken into account by weighting them according to the assumed error of the data. The code is demonstrated on subsurface temperature measurements with different measurement errors. One of the main problems when ordinary kriging is used for 3-D subsurface data is a lack of sufficient data for computing the necessary variograms. A feasible procedure to obtain such a variogram is discussed. The final result of the 3-D interpolated temperature data shows, that the quality of the interpolation increases substantially if the measurement error is taken into account. The code uses a modified GSLIB like input. Although not all functions of the GSLIB kriging library are supported, all substantial functions are available. jk3d is LGPL licensed, open source. The current version is available at http://​sourceforge.​net/​projects/​jk3d.​html.