复杂介质下保真振幅Kirchhoff深度偏移

本文详细讨论地下复杂介质地震成像问题.当速度模型含有强横向变化时，射线场会折叠形成多次走时，在这种情况下，文中证明在保真振幅叠前深度偏移时，应当考虑所有的到时才能得到定量的像.通过实例证明，在多次走时情况下，常规的共炮集、共检波器集都存在强的假像；由此提出共角度偏移的概念.最后，在多次走时下，讨论多次偏移算子(走时、相移、振幅等)的高效重构，给出了三维叠前深度偏移的快速算法.

True amplitude Kirchhoff prestack depth migration in complex media

In this paper,we address the complex geological structures imaging problem,when the velocity macro-model is characterized by very strong lateral variations,and the ray fields may triplicate providing multi-arrivals;we demonstrated that all the multi-arrivals have to be taken into account for a quantitative migration.Furthermore,we propose a common image gather strategy in angle domain to handle the strong artifacts appear in conventional common image gathers(offset or shot domain) when multi-arrivals occurs.In the multi-arrival case,we also propose a high efficient migration algorithm for 3-D prestack multi-arrival depth migration based on the fast reconstruction algorithms for the traveltime, phase rotation and amplitude of the migration operator.