由MT资料反演真谱参数的基本原理

Method for Inversing Real Spectral Parameters Based on Magnetotelluric Method (MT)

常规的大地电磁测深反演方法没有考虑岩矿石激电效应。基于岩矿石激电响应的Dias新模型,分别计算了3层模型的中间层在有极化与无极化2种情况下的视电阻率和相位曲线。结果表明,2种情况下的视电阻率和相位曲线在高频段和低频段基本上重叠,而在中频段有明显的差异。进而研究了从大地电磁测深复视电阻率资料反演地层的真谱参数的方法,推导了层状模型反演的基本公式并给出了相应的具体反演算法。该算法能从MT资料中提取激电谱参数,为解释提供更多的依据。

Excitation effect from rocks is not considered in conventional MT method. Based on a new Dias model of electromagnetic responses, polarization and non-polarization apparent resistivities and phase curves are respectively calculated in a 3 layer model. The result shows that under the conditions stated above the apparent resistivity and phase curves are basically overlapped in high frequency and low frequency bands and it has an obvious difference in middle band. The inversion of real spectral parameters from MT complex apparent resistivity is studied. The basic formula and algorithm for laminar model inversion are derived. The algorithm is to extract the polarizational spectral parameters for providing the basis for interpretation.