DETERMINATION OF THE DISTANCE BETWEEN TWO ADJACENT STATIONS, THE OBSERVATIONAL VERTICAL INCREMENT AND THE OBSERVATIONAL TIME INTERVAL IN OPTIMUM SENSE

Considering the observational error, the truncation error and the requirements of numerical weather prediction, three formulas for determining the distance between two adjacent stations d1, the observational vertical increment △p1 and the observational time interval △t1 in optimum sense, have been derived. Since they depend on the shortest wavelength concerned and the ratio of maximum observational error to wave amplitude, the results are quite different for different scale systems.For the filtered model the values of d1, △p1,, and △t1 in general come near those required in the MANUAL on the GOS published in 1980 by WMO. But for the primitive equation model the estimated value of △t1 is much less than those required in the filtered model case.Therefore, it is improper to study the fast moving and developing processes of the atmospheric motion only on the basis of the conventional observations. It seems to be necessary to establish an optimum composite observational system including the surface-based system and the space-based system.