线源二维瞬变电磁场的正演计算新方法

首先应用有限元直接迭代法,在频域中实现了线源二维电磁场正演计算,然后利用频时转换中较为简便且有效的数字滤波法,实现了频域到时域的转换,从而实现了线源二维瞬变电磁场的正演模拟。该方法具有编程简单,占用内存小,运算速度快和模型输入方便等特点。模拟结果与理论计算结果对比表明,该方法具有较高的计算精度。另外,该方法对复杂条件下的瞬变电磁勘探方法的研究和二维瞬变电磁反演有重要意义。

Forward modeling method of 2D transient electromagnetic field induced by line source

In this paper, Directly Iterative Finite Element Algorithm was used to calculate the electromagnetic components induced by line source on the 2D geo-electric model in frequency domain, and then a convenient and effective digital filter was introduced in the transformation from frequency-domain to time-domain, thus the forward modeling of transient electromagnetic field was achieved. The method features good conveniency of coding, small occupation of storage in computer, faster operation, and simple input of initial model. Comparing with the theoretical results the method showed a good accuracy. This forward method is significant for the study of TEM, and important for 2DTEM inversion.