【摘要】 针对地震记录中的面波通常与体波在初至到时、频率成分以及极化特征方面存在明显差异,而单纯的时间域或者频率域极化滤波方法又无法同时考虑到这些要素,本文提出了一种基于S变换时频域极化滤波的面波压制方法。该方法通过利用多分量地震数据的S变换复系数计算得到多种能够表征数据极化特征的参数,并利用这些极化属性参数来构造滤波器函数。本文选用S变换来设计该极化滤波器是由于它所采用的高斯窗函数的宽度与频率成反比,能够保证每一频率成分所对应的时窗内均包含相同数目的谐波周期,因此,利用S变换可以更加准确地计算出时频域内每一点的局部极化属性。合成数据以及实际数据的处理结果表明本文提出的方法不仅能够有效压制面波,同时还能较好地保护体波。更多还原

【Abstract】 The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequency domain cannot consider all these elements. Therefore, we have developed a time-frequency dependent polarization filter based on the S transform to attenuate the ground roll in seismic records. Our approach adopts the complex coefficients of the S transform of the multi-component seismic data to estimate the local polarization attributes and utilizes the estimated attributes to construct the filter function. In this study, we select the S transform to design this polarization filter because its scalable window length can ensure the same number of cycles of a Fourier sinusoid, thereby rendering more precise estimation of local polarization attributes. The results of applying our approach in synthetic and real data examples demonstrate that the proposed polarization filter can effectively attenuate the ground roll and successfully preserve the body wave.更多还原