Reverse time migration with optimal checkpointing
Reverse time migration with optimal checkpointing
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DOI：
10.1190/1.2742686
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发表时间：
2007-08
期刊：
影响因子：
3.3
通讯作者：
W. Symes
中科院分区：
文献类型：
--
作者：
W. Symes
逆时迁移（RTM）要求以逆序访问在前向时间计算的字段。这种对递归计算字段的无序访问要求存储递归历史的某些部分（检查点），其余部分通过重复部分前向计算来计算。最佳检查点算法选择检查点的方式，使总的存储量最小化为一个规定的水平的额外计算，反之亦然。与非最佳实现相比，最佳检查点大大减少了RTM所需的存储，但代价是计算量略有增加。本文介绍了最佳检查点的形式，既适用于RTM和其他应用程序的伴随状态方法，如建设速度更新叠前波动方程偏移。
Reverse time migration (RTM) requires that fields computed in forward time be accessed in reverse order. Such out-of-order access, to recursively computed fields, requires that some part of the recursion history be stored (checkpointed), with the remainder computed by repeating parts of the forward computation. Optimal checkpointing algorithms choose checkpoints in such a way that the total storage is minimized for a prescribed level of excess computation, or vice versa. Optimal checkpointing dramatically reduces the storage required by RTM, compared to that needed for nonoptimal implementations, at the price of a small increase in computation. This paper describes optimal checkpointing in a form which applies both to RTM and other applications of the adjoint state method, such as construction of velocity updates from prestack wave equation migration.