大地电磁二维层状模型参数化反演

THE MAGNETOTELLURIC PARAMETERIZED INVERSION OF 2-D LAYERED MODEL

本文针对目前二维反演存在求解参数过多和求其偏导数困难的两个问题，在近年来关于连续介质二维大地电磁测深资料快速反演的理论基础上，对二维层状模型反演的目标函数，进行线性近似，采用加权法来近似计算二维模型参数的偏导数。从而实现比较快速的二维层状模型的参数化反演。理论模型的反演试验表明，反演迭代可以较快地以足够的精度拟合视电阻率和相位资料，并收敛接近理论模型。

In this paper, for thetwo problems about the estimation of too many inversion parametersand the difficulties in calculating their partial derivatives in 2-D magnetotelluric inversion,based on the theories of rapid magnetotelluric inversion of 2-D continuous medium,the relati-vely rapid parameterized inverse method of 2-D laycred model was realized by linearly approxi-mating the inverse object funtion of 2-D layered model and by using the weighting method tocalculate their partial derivatives. The results of the inversion for theoretical models show thatthe inverse iteration can fit relatively rapidly and accurately the apparent resistivity and phasedata,and make the obtained inverse model approach theoretical model.