Fourier finite-difference migration
Fourier finite-difference migration
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DOI：
10.1190/1.1443575
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发表时间：
1994-12
期刊：
影响因子：
3.3
通讯作者：
D. Ristow;T. Rühl
中科院分区：
文献类型：
--
作者：
D. Ristow;T. Rühl
现有的许多偏移方案不能同时处理偏移中的两个最重要的问题：陡倾角成像和各方向任意速度变化介质中的成像。例如，相移（ω，k）偏移对几乎所有倾角都是准确的，但它仅限于非常简单的速度函数。另一方面，基于单程波动方程的有限差分格式考虑任意速度函数，但它们衰减陡倾事件。我们提出了一种新的混合偏移方法，称为“傅里叶有限差分偏移”，其中向下延拓算子被分成两个向下延拓算子：一个算子是针对选定的恒定背景速度的相移算子，另一个算子是针对速度函数的变化分量的优化有限差分算子。如果没有速度变化，则仅自动应用相移算子。另一方面，如果有一个强大的变化。
Many existing migration schemes cannot simultaneously handle the two most important problems of migration: imaging of steep dips and imaging in media with arbitrary velocity variations in all directions. For example, phase‐shift (ω, k) migration is accurate for nearly all dips but it is limited to very simple velocity functions. On the other hand, finite‐difference schemes based on one‐way wave equations consider arbitrary velocity functions but they attenuate steeply dipping events. We propose a new hybrid migration method, named “Fourier finite‐difference migration,” wherein the downward‐continuation operator is split into two downward‐continuation operators: one operator is a phase‐shift operator for a chosen constant background velocity, and the other operator is an optimized finite‐difference operator for the varying component of the velocity function. If there is no variation of velocity, then only a phase‐shift operator will be applied automatically. On the other hand, if there is a strong variatio...