波动方程叠前深度偏移方法综述

:对波动方程叠前深度偏移的基本概念、实现方法进行了分类和阐述。波动方程叠前深度偏移方法主要分为2类：一类是单平方根方程偏移,在偏移过程中,上、下行波分别向下延拓,并通过互相关成像条件来提取成像值；另一类是基于“沉降观测”概念的双平方根偏移,在偏移过程中,炮点和检波点同时向下外推,当两者重合时（零偏移距）,零时间的波场值就作为该空间点的成像值。对共炮真振幅偏移进行了阐述,并指出也可以在角度域道集实现该算法。理论模型的处理效果证明，波动方程叠前深度偏移成像技术是解决强横向变速情况下复杂构造成像的一种有效手段。

Review of wave equation prestack depth migration methods

This paper reviewed the concepts of wave equation prestack depth migration and its realizations.Wave equation prestack depth migration can be roughly divided into two:single-square-root equation and double-square-root equation.For the single-square-root equation migration,the up-going and down-going waves are downward continued respectively,and the correlation imaging condition is used.The double-square-root equation is based on the survey-sinking concept,the source and the receiver are downward continued at the same time.When they are on the same place(zero-offset),the wave field value of zero-time is regarded as the migration value of the space point.True amplitude migration is also discussed,and it is pointed that the migration can be realized on common-angle gathers.Theoretical data processing results showed that wave equation prestack depth migration methods are effective tools for complex structure imaging in media of strong laterally varying velocity.