FREQUENCY-DEPENDENT POLARIZATION ANALYSIS OF HIGH-FREQUENCY SEISMOGRAMS
FREQUENCY-DEPENDENT POLARIZATION ANALYSIS OF HIGH-FREQUENCY SEISMOGRAMS
复制标题
DOI：
10.1029/jb092ib12p12664
复制
发表时间：
1987-11-10
期刊：
影响因子：
--
通讯作者：
LINDBERG, CR
中科院分区：
文献类型：
--
作者：
PARK, J;VERNON, FL;LINDBERG, CR
我们提出了一个多锥度算法来估计作为频率的函数的三分量地震数据的粒子运动的偏振。该算法是基于一个奇异值分解的矩阵的特征谱在一个给定的频率。右复特征向量 对应于矩阵的最大奇异值，具有与在该频率处地震运动的主导极化相同的方向。极化矢量的元素 指定在所选频带内沿沿着记录分量测量的运动的相对幅度和相位。该频带的宽度由分析中使用的长椭球锥的时间带宽积确定。我们操纵的组件 以确定视方位角和地震运动的入射角作为频率的函数。本征锥的正交性允许人们容易地计算估计的方位角和入射角的不确定性。我们将该算法应用于Anza地震遥测阵列在0 ≤ Hz ≤ 30 Hz频带的数据。极化并不总是一个平滑的频率函数，可以表现出急剧的跳跃，这表明存在散射模式内的地壳波导和/或接收器站点谐振。
We present a multitaper algorithm to estimate the polarization of particle motion as a function of frequency from three‐component seismic data. This algorithm is based on a singular value decomposition of a matrix of eigenspectra at a given frequency. The right complex eigenvector corresonding to the largest singular value of the matrix has the same direction as the dominant polarization of seismic motion at that frequency. The elements of the polarization vector specify the relative amplitudes and phases of motion measured along the recorded components within a chosen frequency band. The width of this frequency band is determined by the time‐bandwidth product of the prolate spheroidal tapers used in the analysis. We manipulate the components of to determine the apparent azimuth and angle of incidence of seismic motion as a function of frequency. The orthogonality of the eigentapers allows one to calculate easily uncertainties in the estimated azimuth and angle of incidence. We apply this algorithm to data from the Anza Seismic Telemetered Array in the frequency band 0 ≤ ƒ ≤ 30 Hz. The polarization is not always a smooth function of frequency and can exhibit sharp jumps, suggesting the existence of scattered modes within the crustal waveguide and/or receiver site resonances.