基于GPS时间序列分析的地震前后噪声特性差异性研究  

Research on the difference of noise characteristics before and after earthquake based on GPS time series analysis

作　　者：杨登科 YANG Dengke(China Railway Design Corporation,Tianjin 300142 China)

机构地区：[1]中国铁路设计集团有限公司,天津300142

出　　处：《全球定位系统》2021年第2期56-61,92,共7页Gnss World of China

摘　　要：针对现有地震预测研究中噪声特性分析研究较少,就较大地震对GPS时间序列噪声特性的影响进行分析.选取较大地震及相应的临近测站,将GPS时间序列按照时间跨度分为震前4~3 a、前3~2 a、前1~0 a、震后0~1 a、后1~2 a五个时段,分别求取各时段的谱指数,采用不同的噪声模型组合对它们进行噪声特性分析,然后对结果进行对比.结果表明:地震前后谱指数、速度场、振幅相位等变化较大,GPS时间序列噪声特性对地震响应明显;部分测站地震前后谱指数、速度场、周年振幅等较震前1~0 a具有一致性;地震孕育阶段,闪烁噪声+白噪声(FN+WN)在所有最优噪声模型中所占比例上升,闪烁噪声+随机漫步噪声+白噪声(FN+RWN+WN)中FN在所有噪声分量中所占比例上升,震后均下降,与地震时能量释放,地震后站点运动态势恢复常态相一致.According to the fact that there is no enough research of the noise characteristics in the study of earthquake prediction,this paper analyze the influence of large earthquake on the noise characteristics of time series.Focusing on the large earthquake and the corresponding station nearby,the GPS time series were separated to five periods,before the earthquake 4~3 years,3~2 years,1~0 years,after the earthquake 0~1 years and 1~2 years.The spectral index of each period.Noise analysis was implemented using different noise model combination.Analysis results shows that,the change of spectral index,velocity field,amplitude and phase before and after the earthquake is very big,and the noise characteristics of GPS time series are significant to seismic response;For part of the stations the spectral index,velocity field and anniversary amplitude before and after the earthquake is consistent compare with results of the 1~0 years before the earthquake.In earthquake incubation period,the proportion of flicker noise+white noise(FN+WN)increased.And the noise component FN in flicker noise+random walk noise+white noise(FN+RWN+WN)increased among all the noise components.All the ratio decreased after the earthquake,which is in consistent of the earthquake energy release and restoration of the site more meat situation to normal status after the earthquake.

关 键 词：GPS时间序列 地震预测 时序跨度 噪声特性 地震前兆 

分 类 号：P228.4[天文地球—大地测量学与测量工程]