波动方程角度域共成像道集

针对基于波场深度递推的波动方程叠前深度偏移成像方法难以准确地给出如Kirchhoff积分叠前深度偏移成像方法的偏移距域共成像道集的不足,在分析研究现有的各种波动方程偏移成像共成像道集方法的基础上,利用波场外推的单平方根算子和波场的窗口Fourier框架展开与重构方法,提出一种局部角度域共成像道集方法——成像点处反射角共成像道集方法.把这种角度域共成像道集方法应用于国际标准的Marmousi模型数据和一条实际二维地震数据都取得了理想的结果.提出的波动方程反射角度域共成像道集方法可为进一步的叠前偏移数据振幅随角度变化分析和偏移速度分析工作提供基础.

Angle Domain Common Image Gather for Wave Equation

Wave equation prestack depth migration based on wavefield depth recursive extrapolation can hardly give out a common image gather in offset domain as accurately as Kirchhoff integral based prestack depth migration does. In order to make up for this defect, we have analyzed various methods of wave equation migration common image gather. And by using the single square root operator for wavefield extrapolation and the windowed Fourier frame expansion and reconstruction of wavefield, a method for local angle domain common image gather is proposed, i.e. common image gather in reflection angle domain of imaging point. The application of the angle domain common image gather in Marmousi model data and a two dimensional real seismic data yields ideal results. The angle domain common image gather method for wave equation derived in this paper will provide a foundation for further migration velocity analysis and amplitude versus angle analysis of migrated data.