线圈中心近区频率域电磁测深数值模拟研究

Numerical simulation on frequency domain electromagnetic sounding methods in the center of loop

论述了一种在线圈中心测量磁场垂直分量的近区频率域电磁测深方法的原理及一维正演数值模拟研究结果.推导出线圈中心近区频域电磁法的视电阻率表达式,提出了在线圈中心测量磁场垂直分量频域电磁法的基本思路,利用MATLAB编程进行一维正演模拟,先后正演模拟了7种有代表性的地电模型.结果表明:此方法对层状地电构造的电性参数和厚度变化比较敏感,分辨力较高.对二层断面的上层厚度和基底电性分辨,对三层断面的中间层的电性和厚度变化分辨比较清楚,是一种有前景的近区频率域电磁测深方法.

Hydro Mid-South Design Research Institute, Changsha 410014, China） Abstract This paper discussed the principle and one-dimensional numerical simulation result on a sort of new method on frequency domain electromagnetic sounding in the near-field region. Firstly exporting the expression of measuring resistivity of magnetic field vertical component in the center of loop, and including the base ideas of measuring magnetic field vertical component in the center of loop, and making use of MATLAB numerical simulation, orderly one-dimensional numerical simulation seven pieces of representational terra-electroform model, as a result the method sensitive on the layer terra-electroform tectonic electroform parameter and depth change, high differentiate. It is important foreground near-field region electromagnetic sounding that have the first thickness and the middle layer differentiate, and change of electroform and thickness in the mesosphere.