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波散波在地震记录中是一种常见的现象。波散波中包含有许多岩性信息,如表层速度、厚度和吸收系数等。为提取这些信息,本文提出一种波散波的反演方法,包括波散波记录的正演模拟、求取波散曲线和迭代求解过程。波散过程实质上是一个滤波过程。波散波反演就是对波散波记录作纯相位反滤波,使各道反滤波后的波形差在最小平方意义下为最小。这种运算是通过迭代实现的。初值波散曲线可直接由实际记录算出。速代参数修改依波散波类型而异:波散瑞雷波反演时只修改表层横波速度;而勒夫波反演时要修改表层深度。
Wave-scattered waves are a common phenomenon in seismic records. Wave scattered wave contains many lithological information, such as surface velocity, thickness and absorption coefficient. In order to extract this information, this paper presents a method of inversion of wave-scattered waves, including the forward simulation of wave-scattered wave records, the process of obtaining the dispersion curves and the iterative solution. Dispersion process is essentially a filtering process. Wave-scattered wave inversion is the pure phase of the wave-wave recording filter, so that the channel after the inverse of the waveform difference in the least-square sense of the smallest. This operation is achieved through iteration. Initial curve of undulation can be calculated directly from the actual record. The modification of the parameters of the antecedent is different according to the type of wave: the wave velocity of the surface is modified only when the sparse Rayleigh wave is inverted, and the depth of the surface is modified when the wave is inverted.