影响统计插值分析误差的若干因素分析

EFFECT OF SOME FACTORS ON THE ANALYSIS ERROR OF STATISTICAL INTERPOLATION

采用理想观测网,用数值方法计算统计插值分析误差。减小观测误差或初估值误差、增加观测数量、恰当减小观测空间间距、以及选取分布合理的观测资料,有利提高分析精度;如果计算使用的归一化观测误差方差、误差相关函数的特征和总体统计平均情况不一致,有可能造成分析误差的明显增加。最后,利用特征向量分析方法,对归一化观测误差方差、观测误差相关属性对于不同尺度统计插值分析误差的影响进行讨论。

In this paper, a simple numerical experiment of the analysis error of statistical interpolation has been made by using ideal observational network. The experimental results show that the analysis quality of 'OPTIMAL' statistical interpolation can be improved when (1) the observation errors and the first guess field errors are decreased, (2) the number of the observations considered at a grid point is reasonably increased, (3) the distance between neighboring observational stations is become appropriately small, (4) the well-distributed observations are selected, and that the analysis accuracy may be greatly decreased when normal observation errors and. the character of error correlation function used in the calculation are not equal to those on the ensemble average case. Finally the scale response of analysis error has been discussed by using a technique of the eiqenvector decomposition of the prediction error correlation.