地面多分量地震资料纵横波分离方法

SEPARATION OF P-AND S-WAVES IN MULTICOMPONENT SURFACE SEISMIC DATA

由于地表低速带的存在,加上横波速度难以测定,地面多分量地震资料的波场分离比VSP多分量资料的波场分离更为困难.本文提出通过坐标旋转将三分量地面地震资料化为二分量资料,然后在频率-波数域中通过Radon变换、矢量偏振滤波,达到纵、横波分离的目的.受地表低速带影响的剖面,在ι-p域中进行折射校正后,便能消除低速带的影响。本方法具有较强的抗噪能力.

The presence of low velocity zones near surface and the difficulty in obtaining S-wave velocity makes it more difficult to separate wavcficlds in multicomponcnt surface seismic data than in multicomponont VSP data. This paper proposes a method which first reduces 3-componcnt surface seismic data into 2-componant data by means of coordinate rotation, The separation of p-and S-waves for 3-component surface seismic data is then accomplished by Radon transform and vector polarization filtering in f-k domain, The refraction correction carried out in τ-p domain enable us to eliminate the effect of low velocity zones on seismic data. This method has good performance in resistance to noises.