Imaging Condition For Reverse Time Migration
Imaging Condition For Reverse Time Migration
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DOI：
10.1190/1.2370059
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
B. Kaelin;A. Guitton
中科院分区：
文献类型：
--
作者：
B. Kaelin;A. Guitton
逆时偏移是在源波场代表下行波场、接收波场代表上行波场的基本假设下，通过源波场与接收波场的互相关来估计成像条件。然而，对于大的波阻抗对比和复杂的地质构造，波场不能有效地分离。在这些情况下，互相关会导致低频伪影。通过用接收器照明分割每个镜头的互相关图像，可以改善成像条件。这种方法简单，不会引入相移，而且需要很少的额外计算，因为可以从接收波场直接计算接收器的照度。
In reverse time migration the imaging condition is estimated by cross-correlating the source wave-field with the receiver wave-field under the basic assumption that the source wave-field represents the down-going wave-field and the receiver wave-field the up-going wave-field. However, for large impedance contrasts and complex geological structures the wave-fields cannot be separated efficiently. In these cases the cross-correlation leads to low frequency artifacts. The imaging condition can be improved by dividing the cross-correlated image of each shot by the receiver illumination. This method is simple, it does not introduce phase shifts and it requires little additional computation, because the receiver illumination can be directly computed from the receiver wave-field.