基于广义S变换时频滤波的MT数据去噪  

Denoising of MT Data by Time-Frequency Filtering Based on the Generalized S Transform

作　　者：蔡剑华[1] 肖永良 CAI Jianhua;XIAO Yongliang(Cooperative Innovation Center for the Construction&Development of Dongting Lake Ecological Economic Zone,Hunan University of Arts and Science,Changde,Hunan 415000;School of Information Technology and Management,Hunan University of Finance and Economics,Changsha,Hunan 410205)

机构地区：[1]湖南文理学院,洞庭湖生态经济区建设与发展协同创新中心,湖南常德415000 [2]湖南财政经济学院信息技术与管理学院,湖南长沙410205

出　　处：《地质与勘探》2021年第6期1383-1390,共8页Geology and Exploration

基　　金：国家自然科学基金项目(编号:41304098);湖南省自然科学基金项目(编号:2017JJ2192,2021JJ30469);湖南省教育厅重点项目(编号:16A146);湖南省教育厅优秀青年科研项目(编号:18B395);“光电信息集成与光学制造技术”湖南省级重点实验室资助项目联合资助。

摘　　要：针对油气勘探中大地电磁(MT)数据易受各类干扰的污染,且信噪难以分离的问题,把基于广义S变换的时频滤波技术应用于MT数据处理中来,得到MT数据的S域时频分布,分析受噪MT数据在S域的时频分布特征,再在S变换时频域进行时频阈值去噪,并对滤波后的S域时频谱进行逆变换重构,分离得到去噪后的MT数据。给出了基于广义S域时频滤波的方法原理与应用步骤,对被污染的仿真和实测MT数据进行了时频阈值滤波,并与小波阈值去噪方法进行了比较研究。结果表明:基于广义S变换的时频滤波方法可有效抑制MT数据中的干扰,从噪声信号中分离出有效的大地电磁数据,且减少了人为参与,提高了MT勘测的数据质量。This work attempts to solve the problem that magnetotelluric(MT)data in hydrocarbon exploration are prone to contamination by various interferences and it is difficult to separate signal and noise.The time-frequency filter based on the generalized S transform is applied to MT data processing.Firstly,the time-frequency distribution of the MT data in the S domain is obtained,then the time-frequency threshold denoising is performed,and the denoised time-frequency spectrum of the data is reconstructed by inverse transform.In this paper,the principle and method of the time-frequency filtering based on generalized S domain are given.The simulated and measured MT data contaminated by interferences are processed with time-frequency filtering.And the proposed method is compared with the wavelet transform method.Results show that the time-frequency filtering method based on the generalized S transform can effectively suppress the interference and separate the MT data from the signal bearing noise.The proposed method improves the quality of MT data.

关 键 词：广义S变换 大地电磁数据 时频分析 去噪 阻抗估计 

分 类 号：P631.3[天文地球—地质矿产勘探]