水平层状介质下瞬变电磁成像方法

Method of Transient Electromagnetic Imaging in Horizontal Layered Medium

为提高瞬变电磁法的对地探测精度,从瞬变电磁场的传播特性和电磁响应特性两个角度考虑,提出了瞬变电磁成像方法:由野外实测磁场感应数据,经过反褶积和线性数字滤波求出波阻抗;用线性规划法求出每一微层走时所对应的反射系数序列,并以此为参数绘制成像结果图.对理论模型和实例资料的成像处理结果表明,采用瞬变电磁成像方法的成像处理结果比常规的瞬变电磁视电阻率处理剖面清晰、直观,大大增强了由瞬变电磁资料识别地下电性层状分界面的能力.

In order to improve the prospecting precision to the earth of transient electromagnetic method (TEM), the idea of TEM imaging is proposed according to the characteristics of both electromagnetic wave propagation and response: the waveimpedance is calculated from observed data infield by the way of inversefaltung and linear digital filter; the sequence of reflection coefficients corresponding to every tinylever move time is calculated by the way of linear programming, and the imaging result section is drawn consequently. The imaging result obtained from theoretical model and real example indicates that the proposed method can improve greatly the ability to recognize the underground electric interface of TEM compared with the regular processed resistance section.