大地电磁资料偏移成像  

A NEW METHOD OF MIGRATION AND IMAGING FOR MT DATA

作　　者：宋维琪[1] 邹文勇[2] 

机构地区：[1]石油大学(华东)地球资源与信息学院,中国山东东营257061 [2]中石化胜利油田地质科学研究院,中国山东东营255075

出　　处：《地震学报》2005年第1期102-108,共7页Acta Seismologica Sinica

摘　　要：　在研究Zhdanov的二维电磁场偏移成像的基础上, 针对它在某些方面的不足, 研究并提出了改进算法. 首先, 用一维反演结果确定初始背景电阻率, 然后在延拓计算过程中, 利用迭代算法进行逐层修正、延拓计算, 从而获得较准确的电阻率; 第二, 研究了有限差分方程的改进算法, 根据大地电磁场变化的特点, 设计了纵向以等比级数变网格的迭代算法. 通过以上两方面技术的改进, 经理论模型和实际资料试算验证, 取得了较好的结果.Based on the study on electromagnetic field migration by Zhdanov, we have proposed an improved method for the weak points in the research. Firstly, the initial background resistivity is determined by using 1 D inversion results. Then in the process of continuation, the results are corrected and calculated layer by layer by the iteration method, so that more exact resistivity can be obtained. Secondly, an improved algorithm for finite difference equation is studied. According to the property of electromagnetic migration field, the algorithm is designed by means of grids varying with geometric progression in the longitudinal direction. Being improved by the techniques mentioned above, better results are obtained by the new method, which has been verified by both the theory model and practical data.

关 键 词：大地电磁资料 有限差分法 数值计算 偏移成像 

分 类 号：P318.2[天文地球—固体地球物理学]