瞬变电磁的逆时偏移成像方法

Transient electromagnetic inverse time migration imaging method

本文研究了中心回线瞬变电磁测深的逆时偏移成像问题。针对电磁波在大地中的传播速度远小于真空中的光速这个特性,设计了一种适用于中心回线观测方式瞬变电磁测深的逆时偏移成像的算法,其核心思想是根据不同观测点在成像点相同时刻的波场值的叠加,进而获得成像点的总波场值。基于该算法,对一条实测的中心回线瞬变电磁测深资料进行了逆时偏移成像处理,结果表明,逆时偏移成像结果与实际情况比较吻合,得到了比较好的处理效果。因此,逆时偏移成像方法是瞬变电磁测深法的一种比较有效的资料处理方法。

In this paper,inverse time migration imaging of center loop transient electromagnetic sounding is studied.In view of the fact that the propagation velocity of electromagnetic wave in the earth is much lower than that of the speed of light in the vacuum,an inverse time migration imaging algorithm is designed which is suitable for transient electromagnetic sounding in the center loop observation configuration.The core idea of the algorithm is to obtain the total wave field value of the imaging point according to the superposition of the wave field value of different observation points at the same time of the imaging point.Based on this algorithm,inverse time migration imaging was performed on a measured center loop transient electromagnetic sounding data.It is shown that the results of inverse time migration imaging are in good agreement with the actual situation and can obtain better processing effect.Therefore,inverse time migration imaging is an effective data processing method for transient electromagnetic sounding.