大地电磁阻抗估计方法对比.pdf

第23卷第9期
中国有色金属学报
2013年9月
Vol 23 No 9
The Chinese Journal of Nonferrous Metals
Sep.2013
文章编号:1004-0609(2013)09-2351-08
大地电磁阻抗估计方法对比
汤井田,张弛,肖晓,刘祥
(中南大学地球科学与信息物理学院有色金属成矿预测教育部重点实验室,长沙410083)
摘要:比较了几种大地电磁阻抗估计方法的性能。为了给阻抗估计结果提供对照标准,首先介绍大地电磁模拟
数据的生成方法,并从含噪数据中提取典型的噪声时间序列;然后介绍最小二乘估计、M回归估计、有界影响估
计和重复中值估计这4种回归方法的基本原理,并用一组标准数据测试了它们的性能:最后采用4种估计方法处
理不同程度加噪的模拟数据,与模拟结果进行比较。结果表明:重复中值估计的稳健性最优;当磁道存在噪声时,
有界影响估计给出了明显优于M回归估计的结果,也能满足要求。因此,在实测数据处理中,推荐使用重复中
值估计方法与有界影响估计方法。
关键词:大地电磁;稳健阻抗估计;M回归估计:有界影响估计;重复中值佔计
中图分类号P631.3
文献标志码:A
Comparison of methods for magnetotelluric impedance estimation
TANG Jing-tian, ZHANG Chi, XIAO xiao, LIU xiang
(Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
School of Geoscience and Info-physics, Central South University, Changsha 410083, China)
Abstract: The performances of different kinds of methods for magnetotelluric impedance estimation were compared. The
method of generating magnetotelluric simulated data was introduced, the typical noise series was extracted from nois
data. The basic principles of for re resin metods of least square estimator, M-re ression estimator, bounded influence
estimator and repeated median estimator were introduced. These methods were tested using a set of standard data. At last
simula ed data added by noise at ifferent levels were processed by the four different estimators and compared with the
simulated results. The results show that the repeated median estimator is the most robust. When the noise exists in the
magnetic channel, the results estimated by the bounded influence method are acceptable, which are more stable than
those estimated by the M-re ression method. So, in the magnetotelluric data processing, the repeated median method and
bounded influence method are recommended
Key words: magnetotelluric; robust estimation; M-regression estimation; bounded influence estimation; repeated median
estimation
大地电磁测深法( Magnetotelluric,MT)自20世纪约大地电磁法应用的因素。随着人类社会经济活动的
50年代诞生起,就以勘探深度大、无需人工场源的优不断开展,人文电磁噪声益严重,特别是在人烟稠
势成为矿产资源劫査、地下水和地热勘探、油气普查、密的工业发达地区,高压电网、电视塔、各种金属管
地震预报、地壳及岩石圈深部结构探测等领域不可或网、广播电台、雷达、通讯电缆及信号发射塔等造成
缺的重要地球物理方法之一。但也正是大地电磁测深的电磁干扰,严重污染了实际的大地电磁信号,极大
利用天然场源的原因,低信噪比、易受干扰始终是制地影响了大地电磁数据质量和应用效果。因此,如
基金项目:国家科技专项“深部探测技术与实验硏究专项”( Sinoprobe03);国家自然科学基金资助项目(40874072,41104071)
收稿日期:2013-05-16;修订日期:2013-06-30
通信作者:汤井田,教授,博士;电话:13507317396;E- mail: ittang(@mail,csu.edu,cn