互易定理在平面波偏移成像中的应用

与常规炮域波动方程偏移相比,平面波偏移可以用较少的计算量得到同等质量的成像结果。然而,单边接收方式常常影响这种偏移方法的应用效果,双边观测才是适用于平面波偏移的最优观测方式。系统分析了单边观测方式对平面波偏移的影响,基于互易定理提出了两种将单边数据转为双边数据的方法,通过数值模拟验证了方法的正确性。同时,研究了互易定理在双边观测数据中的应用效果,认为互易定理提供了一种内插模式,可以克服共检波点道集的空间假频问题,改善平面波偏移质量。对标准Marmousi模型炮集数据应用互易定理前后的效果作了对比分析,结果表明,应用互易定理能够明显提高平面波偏移质量,同时减小了计算量。最后,用实际数据平面波偏移结果证实了上述结论。

Application of reciprocity principle on plane wave migration

Compared with conventional shot migration,plane wave migration can achieve the same-quality imaging with much less computation cost.However,single ended spread often affects the result of the migration.Therefore,we reviewed the influence of single ended spread on plane wave migration.According to the reciprocity principle,we developed two methods to transform single-ended spread record into artificial split spread record,and carried out numerical simulation to verify the effectiveness of the methods.Meanwhile,we applied the reciprocity principle on artificial split spread record,which indicates that reciprocity principle provides one interpolation pattern to overcome the spatial alias and improve the quality of plane wave migration.Then,the reciprocity principle was tested on the standard Marmousi model.The result shows that the application can obviously improve the quality of plane wave migration and reduce computation.Finally,the above achievements were verified by the application of actual data.