三分量地震资料的偏振分析

Polarization analysis of three-component seismic data

将奇异值分解运用于三分量地震资料矩阵中,得到了径向能量这一具有物理内涵的数学表达式.证明了资料矩阵的总能量可用奇异值的平方和来表达,以及P波到达的径向能量最大值在第一奇异向量方向出现.据此得到偏振属性,其中最显著的特点P波出现在径向能量接近于最大的地方,这可以给弱信号提供较准确的到时.为发展同时利用偏振和频散资料的联合反演不同周期面波相速度的横向不均匀分布这一新的反演方法提供偏振分析的基础数据.

Applying singular value decomposition in a matrix of three-component seismic data, we obtained the mathematical expression of the radial energy with definite physical connotation, and demonstrated that the total energy of the data matrix is expressed by the square sum of a singular value. Therefore the maximum of the radial energy during the P-wave arrive appears in the direction of the first singular vector. In view of the above, the polarization attributes are obtained. Of them the most remarkable feature is that P-wave emerges in the point there the radial energy is close to maximum. It is possible to pick the more accurate arrival time for a weak signal, and to supply simultaneously inverting the lateral inhomogeneity of the surface wave phase velocity with different periods using polarization and dispersion data with fundamental data on the polarization analysis.