UVKRIG - A FORTRAN-77 PROGRAM FOR UNIVERSAL KRIGING

The application of universal kriging to weakly stationary data is difficult for three reasons: (1) it is difficult to estimate the variogram for the weakly stationary data; (2) the order of drift for weakly stationary random function must be modeled; and (3) equation solution differs for universal kriging from that for simple or ordinary kriging. UVKRIG, a FORTRAN-77 computer code presented herein, offers a cross-validation procedure to help resolve the first two difficulties. A relatively simple maximum pivot search Gauss elimination algorithm is used to solve universal kriging equations. Application of UVKRIG to a weakly stationary data set for cross-validation and gridding is described. © 1990.