提出水平层状横向同性地层中频率测深资料的全参数快速迭代反演算法,以便从测量资料中同时确定各个地层的横向、纵向电导率及层界面深度.首先,利用水平层状介质中电磁场并矢Green函数在频率波数域中的解析解和Sommerfeld积分的快速计算技术确定正演响应.然后,利用摄动理论和Fourier逆变换公式,研究建立一套快速求解全参数Fr6chet导数的有效算法,并利用规范化处理和奇异值分解技术给出迭代反演过程.最后,给出数值试验证明反演理论的有效性以及反演算法的抗噪声能力.
In this paper, we advance a fast iterative inversion algorithm of frequency electromagnetic sounding data to simultaneously reconstruct the horizontal and the vertical conductivities and interface each bed in the horizontally stratified transversely isotropic (TI) medium. First, applying the analytic expression of the electromagnetic dyadic Green's functions in the TI medium, we realize the forward modeling of the frequency sounding via the fast algorithm of Sommerfeld integral. Then using the perturbation principles and Fourier inversion transform, we establish an efficient computation of Fr6chet derivatives of the frequency sounding data with respective to all the model parameters. And we use the least square criterion, the normalization and singular value decomposition to iteratively recovery all model parameters. Finally, numerical results validate the inversion algorithms and their antinoise ability.