在正常情况下,许多前兆观测资料可视为一个平稳的时间序列。在发生强震的时期,由于地壳及有关的地球物理场发生剧烈变化,这种平稳性才遭到破坏。问题在于如何从震前的、基本上是平稳的数据序列中找出统计性质的变化,预测强震的发生。对平稳过程而言,除常数均值外,自相关系数是其最重要的统计特征。计算相关系数,并考察它 Under normal conditions, many precursor observations can be viewed as a smooth time series. In the period of strong earthquakes, the stability was destroyed due to the drastic changes in the crust and related geophysical fields. The question is how to find out the changes in statistical properties from pre-earthquake, essentially stationary data series and predict the occurrence of strong earthquakes. For the stationary process, except for the mean of the constants, the autocorrelation coefficient is the most important statistical feature. Calculate the correlation coefficient and examine it