波动方程正反向延拓滤波

Wave equation downward and upward continuation filtering

1. 中国科学院地球物理研究所, 北京 100101;2. 中国地质大学 北京, 100083

Institute of Geophysics, Academia Sinica, Beijing 100101

压制面波等干扰波,提高信噪比,是地震数据处理中的一个重要内容。本文提出一种全新的方法,利用波动方程正反向延拓进行滤波。该方法基于这样一种思想：将他表记录通过波动方程正向延拓至一定深度,在此深度上,面波等干扰波分布于浅层,而有效反射保持在原来的层位,将浅层的波场置零后,再反向延拓记录至地表,达到消除干扰的目的。本文对该方法的原理及计算方法都进行了比较详尽的讨论,实际资料处理表明,该方法是正确和可行的。

Raising signal-to-noise ratio by suppressing ground roll and other noises is an important subject in seismic data processing. In the paper, a new method which uses wave equation downward and upward continuation to perform filtering is presented. The method is based on the following idea: The surface seismogram is downward continued to a certain depth by wave equation downard continuation method;on the depth, ground roll and other disturbing waves propagate in the shollow layers, and effective reflection waves propagate in the original layers; after the wavefield in the shallow layers is zeroed, the seismogram is reversely continued to the surface. In this way, ground roll and other disturbing waves are removed. Both the theory and calculation of the method are discussed in detail. Real data processing demonstrates that the method is correct and feasible.