【摘要】 由共成像点道集抽取的共偏移距道集可以当成相同地下成像的多次观测.由于偏移误差的影响,在不同共偏移距道集上,同一采样点存在水平和垂直方向上的错位.本文提出一种基于地震图像校准的共成像点道集增强技术,实现了不同偏移距道集在时间和空间上的逐点匹配对齐.在本文中以2D局部归一化互相关来表征共偏移距道集和叠加道集在相同时空位置的相似度,假设在不同水平和垂直移动量时的互相关满足连续凸函数,利用求导方法估计共偏移距道集在该位置处的非整数校正量,最后采用双线性内插方法估计成像振幅.传统道集拉平技术在垂直方向进行校正量消除,本文方法能有效估计共偏移距道集中的水平和垂直校正量,并在亚像素域估计正确的成像振幅.模型数据和实际数据的处理结果表明,本文方法能有效增强共成像点道集中同相轴的一致性,提高叠加结果的分辨率.更多还原

【Abstract】 The common offset gathers extracted from common image gathers can be seen as multiple observations about the same underground image.Due to migration errors,the real image positions deviate from the true positions with lateral and vertical misalignments.This paper proposes a seismic image warping technique to enhance the common image gathers.This method aligns different common offset gathers point to point in both the lateral and vertical direction.In this paper the 2D local normalized cross-correlation can be used to measure the similarity of the input gather and the model gather at the same temporal and spatial position.By assuming the 2D cross-correlation computed at various lateral and vertical relative lags satisfies a continuous convex function,the derivation method can be used to estimate the non-integer correction values corresponding to the maximum correlation at the given position.After that the accurate image amplitude can be estimated by the bilinear interpolation.Compared with the traditional gather flattening method,the proposed method can estimate the lateral and vertical correction values of the common offset gathers and obtain the accurate imaging amplitude in the sub-pixel domain.The processing results of the 2D synthetic and real dataset demonstrate the proposed method can enhance the event consistency of common image gathers and improve the resolution of the stack.更多还原