Spurious multiples in seismic interferometry of primaries
Spurious multiples in seismic interferometry of primaries
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DOI：
10.1190/1.2211507
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发表时间：
2006-08
期刊：
影响因子：
3.3
通讯作者：
R. Snieder;K. Wapenaar;K. Larner
中科院分区：
文献类型：
--
作者：
R. Snieder;K. Wapenaar;K. Larner
地震干涉术是一种通过将接收器上记录的波相互关联来估计格林函数的技术，格林函数解释了接收器之间的波传播。我们给出了这一原理的一种基于驻相方法的推导。虽然这一推导是为了教育，只适用于简单的介质，但它提供了对地震干涉测量的物理原理的洞察。在有一个水平反射面和没有自由面的均匀介质中，两个接收器记录的波的相关正确地给出了直达波和单次反射波。当存在更多的反射体时，单次反射波的乘积出现在互相关中，当波仅在表面激发时，这会导致虚假倍数。我们给出了一个启发式的论点，当包括反射器下方的源时，这些虚假倍数就消失了。我们还将其推广到平滑变化的非均匀背景介质中。
Seismic interferometry is a technique for estimating the Green’s function that accounts for wave propagation between receivers by correlating the waves recorded at these receivers. We present a derivation of this principle based on the method of stationary phase. Although this derivation is intended to be educational, applicable to simple media only, it provides insight into the physical principle of seismic interferometry. In a homogeneous medium with one horizontal reflector and without a free surface, the correlation of the waves recorded at two receivers correctly gives both the direct wave and the singly reflected waves. When more reflectors are present, a product of the singly reflected waves occurs in the crosscorrelation that leads to spurious multiples when the waves are excited at the surface only. We give a heuristic argument that these spurious multiples disappear when sources below the reflectors are included. We also extend the derivation to a smoothly varying heterogeneous background medium.