大地电磁资料精细处理和二维反演解释技术研究（四）——阻抗张量分解的多测点-多频点统计成像分析

基于大地电磁阻抗张量分解技术，本文提出了两种电性主轴方位的统计描述图像：随频率变化的统计分布成像（频率分布云图）和随测点序列变化的统计分布成像（测点分布云图）.这两种图像与传统的统计玫瑰图一起，较全面地描述了最佳主轴的分布特征.在进行构造维性分析过程中，通过定义二维有效因子e_2d，来压制一维结构和三维结构、突出纯二维结构的影响.e_2d被用于电性主轴的统计加权，有效地起到了滤波的作用；同时，统计成像中还考虑了数据质量的影响.为了得到稳定、高质量的区域阻抗张量数据，提出并实现了共主轴的多测点-多频点阻抗张量分解新算法.最终，完成了以上各项处理手段的可视化实现.本文通过两个理论模型和一个实测算例，以共轭阻抗法（CCZ法）为基础，展示了这一新技术的有效性.

Refined techniques for magnetotelluric data processing and two-dimensional inversion (IV)：Statistical image method based on multi-site,multi-frequency tensor decomposition

Based on magnetotellueic (MT) tensor decomposition technique, in this paper, two statistical image approaches are proposed to analyze the geo-electrical strike. One is the statistical map of variation of strike with frequencies (Strike-Frequencies map), the other is variation of strike with sites (Strike-Sites map). Distribution feature of strike direction can be comprehensively described according to these two image results and traditional rose diagrams. In dimensional analysis, two-dimensional (2D) effective factor e_2d is advocated to overcome the effects of 1D and 3D structure and yield responses representative of 2D regional scale structures. e_2d is used in statistical computation for the geo-electrical strike, which plays an effectively filtering role. At the same time, the effects of data quality are taken into account in our statistical image approaches. In order to obtain robust and high-quality regional impedances, a novel multi-site, multi-frequency tensor decomposition method with fixed strike direction is proposed. Finally, the visualization of all above approaches is realized through programming. With conjugate impedance method (CCZ), the above analysis is applied to two synthetic data sets and to a field data, which exemplifies the effectiveness of the proposed approaches.