用瞬变电磁法识别地下电性分界面

提高瞬变电磁法责料的解释精度一直是该方法推广应用的关键。文中提出了基于反射系数的瞬变电磁地下介质电性分界面的识别方法，并给出了数学模型。由所测磁场数据在频率域内数字滤文技术计算波阻抗，再通过域的变换在时间域内建立含有反射系数的线性方程组，并解出各时间道所对应的反射系数，最终以此值为参数绘制剖面图。两个模型和一个实测数据的数值模拟计算结果表明，本文提出的方法正确、有效，并大大提高了瞬变电磁对地下电性层的分辨能力。

Recognizing electrical interface with the transient electromagnetic method

It is the key of enlarging application of TEM to improve the interpretation accuracy.It has been put forward that the geoelectrical interface of underground medium can be recognized by reflection coefficient.The mathematics model has beem raised.Beginning with the data observed in field,calculating wave impedance with the technical of digital filter in frequency domain,and after domain transform functions that contain reflection coefficient have been constructed in time domain.At last reflection coefficient corresponding to each time gate has been computed.The section of the parameter has been drawn.The result of two numerical modeling and example application shows that the thought is right and efficient.The distinguishing capacity of TEM to geoelectrical layer is improved using the method.