【作者】 周志军；

【导师】 戴前伟；

【作者基本信息】 中南大学 ， 地球探测与信息技术， 2011， 硕士

【摘要】 EH4连续电导剖面仪是由美国EMI公司生产的电磁法仪器系统,这套仪器既可以使用天然场源的大地电磁信号,又可以使用人工场源的电磁信号,其基本原理是通过采集地球物理电场和磁场分量,利用Cagniard提出的计算视电阻率的方法来计算出视电阻率,以此获得地电断面的电阻率等值线图,来研究地质构造情况。该仪器可以有效地应用于地下水的调查,环境研究、矿产和地热的勘探及城市建设中地下工程的应用。由于数据采集量大、设备轻便、工作效率高等,EH4系统是近年来普遍应用的电磁法仪器之一,但目前的生产实际当中,数据处理基本上依赖于该系统自带的基于DOS界面的数据采集和处理软件来进行简单的一维反演、然后进行二维拟地电断面的成图分析。本文基于此现状,简要的介绍了EH4电磁测深方法的国内外研究现状,主要针对EH4采集的时间域数据和频率域数据分析,并利用正则化反演方法进行了应用研究分析。本文首先以EH4电磁测深系统的原理是基于高频大地电磁理论,分析了均匀半空间、层状介质为例推导了其基本理论和正反演基本思路,研究了时间域内EH4时间序列读取、时频转换、功率谱估算、阻抗估算等数据处理方法技术,具体包括Y文件的读取过程、FFT时频转换原理、汉宁窗口对野外实测数据的滤波及功率谱的计算等等,然后针对实际情况介绍了频率域内一维连续介质的正反演的算法推导,并利用Matlab编程语言编写了代码,具体包括模型理论分析、算法验证等等；为了说明本文的野外实用性,本文最后以某煤矿采空区探测为例,利用测区地质、地球物理情况,圈定了若干区域的异常分布,验证了本文EH4系统的时域与频域数据处理及应用的有效性。更多还原

【Abstract】 The Stratagem system is a magnetotelluric system made by EMI Inc. The device can use not only the natural source magnetotelluric filed, but also the user workshops source of electromagnetic signals, through collecting geophysical electric and magnetic field components, the apparent resistivity is calculated, in order to obtain the geological structure and resistivity contour of geoelectric section. In U.S Stratagem measurements may be effectively applied in ground water investigation, research in environment, mineral and geothermal exploration, and in civil engineering studies. In recently years EH4 system become more and more popular in magnetotelluric filed because of abundance data collection, portability equipment and high work efficiency. Although EH4 has been widely used in china, in the current actual production, it’s data processing mostly depend on IMAGEM which is manufacturer’s software of data collecting and data processing.The background and purposes of research are introduced in this paper, research status of EH4 electromagnetic at home and abroad is presented briefly. It is mainly for the time domain data and frequency domain data to analysis, and use the regularization inversion method to research and analysis. EH4 electromagnetic sounding system principle is based on high-frequency magnetotelluric theory, the basic theory of homogeneous half-space, layered medium is derived. Reading of time series, time and frequency conversion, power spectrum and impedance estimation have been studied in time domain.Specifically including the reading process of Y documents, FFT time-frequency conversion principle, Han-ning window filtering of field survey data and the calculation of power spectrum, etc. In frequency domain, one-dimensional continuous medium inversion is derived and the program is written using Matlab programming. Finally, to illustrate the practicality of this field, through specific examples-Coal Mine detection, the abnormal distribution of several regions is determined by measuring geological, geophysical conditions. So the effectiveness of the time domain and frequency domain data processing is verified.更多还原