山区MT资料处理新技术及效果

New technology and effects of mountainous MT data processing

山区MT资料不可避免地会受到各种干扰及地形与局部异常体的影响。针对此问题,本文提出了山区MT资料处理与解释新方法:①利用基于支持向量机回归算法去噪,此法对消除部分测点的地形和局部异常体的影响有一定的作用;②使用了大地电磁二次函数逼近全局最优的非线性一维反演技术构造二维反演的初始地电模型;③采用山地二维反演技术对按实际地形构造的二维地电模型进行TE、TM联合二维反演。经实测资料处理结果表明,用本文所述方法得到的地电剖面不仅地层分层清晰,而且各层之间有很好的对比性,而以往用常规方法处理的地电剖面的规律性比较差。

The MT data in mountainous area inevitably suffered from the various interferences and influence of topography and local anomalous bodies. In view of this issue, the paper presented new mountainous MT data processing and interpretation approaches: ①using regression algorithm based on supporting vector computer for denoise, which plays some role in diminishing the influence of topography at a part of survey points and local anomalous bodies; ②using 1-D non-linear inversion that approaches global optimum by MT second-order function to construct initial geoelectric model of 2-D inversion; ③using 2-D mountainous inversion technique to carry out 2-D TE and TM combination inversion for 2-D geoelectric model based on practical topographic structure. It is shown by processing results of surveyed data that geoelectric sections yielded from the approach presented by the paper were characterized by not only identified stratigraphic division, but also good correlation among separate strata, in contrast, the regularity of geoelectric sections processed by former ordinary approach was poorer.