ISSN 1004-4140
CN 11-3017/P

基于先验信息约束的Curvelet域地震数据POCS插值方法

Seismic Data Reconstruction Based on the POCS Method in the Curvelet Domain with Prior Information

  • 摘要: 由于野外采集环境的限制,常常无法采集得到完整规则的野外地震数据,为后续地震处理、解释工作的顺利进行,需要进行地震数据重构。凸集投影(POCS)方法利用地震波形在Curvelet域的稀疏特性,可以重构出高信噪比地震数据,该迭代算法稳定,其收敛速度较快。但在地震数据恢复的时候,由于直达波和炮集上部空白区域的影响,随着迭代的进行,重构数据中噪声干扰越来越严重,导致最终恢复的地震数据信噪比较低。本文在实现POCS迭代阈值算法基础上,引入先验信息约束的思想对算法进行优化。通过先进行坐标映射的方法进行炮集插值,然后将其作为先验信息约束进行插值,可以有效地压制迭代噪音对重构地震波形数据的影响。通过合成地震炮记录与实际炮集进行测试,结果表明本文提出的改进方法可以明显改善重构地震数据的信噪比,并提高地震波场同相轴的连续性。

     

    Abstract: Due to limited acquisition conditions in the field, the seismic data is usually incomplete, which affects the following seismic data processing and seismic interpretation. To solve this problem, the seismic data needs reconstruction. The projection onto convex sets (POCS) method utilizes the sparse characteristics of seismic waveforms in the Curvet domain to reconstruct high signal-to-noise ratio seismic data. This iterative algorithm is stable and has a fast convergence speed. However, during the recovery of seismic data, because the influence of direct waves and the blank area in the upper part of the shot gathers as the iteration progresses, the noise interference in the reconstructed data becomes increasingly severe, resulting in a low signal-to-noise ratio of the final recovered seismic data. Based on the implementation of the POCS iterative threshold algorithm, this article introduces the idea of Prior information constraints to optimize the original algorithm. By first performing coordinate mapping for shot gathers interpolation and then using it as a prior information constraint for interpolation, the impact of noise attenuation is dramatic. Finally, the synthesized seismic shot records were tested with actual shot gathers, and the results illustrated that the new method proposed in this paper can significantly improve the signal-to-noise ratio of reconstructed seismic data and enhance the continuity of seismic wave field events.

     

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