Stochastic interpolation of rainfall data from rain gages and radar using Cokriging: 2. Results

Various estimation procedures using ordinary, universal, and disjunctive cokriging are evaluated in merging rain gage measurements and radar rainfall data. The estimation procedures and the simulation experiments were described in part 1 (Seo et al., this issue) of this two-part work. In this part, the experiments are described in detail. An objective comparison scheme, devised to compare a large number of estimators, is also described. The results are presented focusing upon (1) the potential of radar-gage estimation using cokriging over radar-only estimation and gage-only estimation under widely varying conditions of gage network density and the error characteristics of radar rainfall, (2) the potential for using universal or disjunctive cokriging over ordinary cokriging, (3) how the uncertain second-order statistics affect the estimators, due to lack of rain gage measurements, and (4) how the statistical characteristics of ground truth rainfall affect the estimators.