Kinematic artifacts in prestack depth migration
Kinematic artifacts in prestack depth migration
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DOI：
10.1190/1.1707076
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发表时间：
2004-04
期刊：
影响因子：
3.3
通讯作者：
C. Stolk;W. Symes
中科院分区：
文献类型：
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作者：
C. Stolk;W. Symes
偏移速度模型中的波的强折射引入了运动学伪影？相干事件不对应于实际的反射器？转换成由应用于各个数据面元的叠前深度偏移产生的图像体。由于各个bin是独立迁移的，因此迁移无法访问慢度的bin分量。慢度信息的这种损失允许事件沿沿着多个入射-反射射线对迁移，从而将伪相干事件引入到图像体积中。这种病理发生在所有常见的分箱策略中，包括共源、共偏移和共散射角。由于伪影随面元参数一起移出，因此它们对最终叠加图像的影响是最小的，只要偏移速度模型在运动学上是正确的。然而，即使采用运动学精确的偏移速度模型，共成像道集也可能表现出具有大量剩余时差的高能一次同相轴。
Strong refraction of waves in the migration velocity model introduces kinematic artifacts?coherent events not corresponding to actual reflectors?into the image volumes produced by prestack depth migration applied to individual data bins. Because individual bins are migrated independently, the migration has no access to the bin component of slowness. This loss of slowness information permits events to migrate along multiple incident-reflected ray pairs, thus introducing spurious coherent events into the image volume. This pathology occurs for all common binning strategies, including common-source, common-offset, and common-scattering angle. Since the artifacts move out with bin parameter, their effect on the final stacked image is minimal, provided that the migration velocity model is kinematically correct. However, common-image gathers may exhibit energetic primary events with substantial residual moveout, even with the kinematically accurate migration velocity model.