利用噪声互相关技术计算福建台网台站绝对钟差

Calculating the Absolute Clock Difference of Fujian Station Network Station by Using Noise Cross-correlation Technology

利用福建省地震台网的88个测震台2018年1月1日—2018年12月31日的噪声记录,通过互相关技术得到台站对间格林函数,将长期叠加结果作为每对台站的参考格林函数。将短期互相关格林函数与对应的参考格林函数再做互相关,即可求出台站间相对钟差。依据相对钟差与单台钟差的关系,建立一个由系数矩阵、待求单台绝对钟差及台站对间相对钟差组成的超定方程组,基于最小二乘法求解方程组,得到单台绝对钟差。为验证结果的准确性,选取了2018年福建省内以及附近地区的一些地震事件,运用单纯型法定位,得到的台站走时残差与计算钟差进行对比,结果显示利用噪声计算的钟差能真实反映台站记录的时钟偏差。

In this paper,the noise records of 88 seismic stations of the Fujian Provincial Seismic Network from January 1st,2018 to December 31th,2018 are utilized.And the inter-pair Green’s function is obtained by cross-correlation technology,which will be superimposed for a long time.The result is used as a reference Green’s function for each pair of stations.By correlating the short-term cross-correlation Green’s function with the corresponding reference Green’s function,the relative clock difference between stations can be obtained.According to the relationship between the relative clock error and the single clock difference,an overdetermined equation system consisting of a coefficient matrix,a single absolute clock difference to be determined,and a relative clock difference between the stations is established.Solving the system of equations based on the least squares method,and obtaining a single absolute clock difference.In order to verify the accuracy of the results,some seismic events in and around Fujian Province in 2018 were selected by simple method.The obtained travel time residuals were compared with the calculated clock differences.The results show that the clock difference can be calculated by using noise.