摘要
由于深部地质目标的瞬变电磁响应被淹没在噪声之中,使得实测数据的晚期信号较弱且振荡剧烈,因此研究TEM信号消噪方法有着重要意义。通过研究瞬变电磁场的特点,用常规三点指数逼近非线性平滑去噪方法、ICA降噪方法和多尺度小波分析方法分别对理论模拟曲线和实测数据进行消噪处理。通过对比分析,结果表明针对理论模拟曲线,采用Sym6小波、硬阈值函数、5层分解的小波降噪方法能取得满意的去噪效果,SNR可提高3～9dB;针对实测数据,小波分析的方法也能有效地分离有用信号和噪声,使晚期数据平滑很多。
The transient electromagnetic response of deep geological target is submerged in noise so that late signals of measured data are weak and have violent oscillation. Therefore, the research on TEM signal de-noising methods has important significance. De-noising methods, including three-point exponential approximation nonlinear smooth denoising method, ICA de-noising method as well as wavelet analysis, are used to process theory simulation curve and measured data in this paper based on the characteristics of TEM signal. The comparative analysis show that the wavelet denoising method with Sym 6 wavelet, 5 layer decomposition and hard threshold function can get the satisfactory de-noising results. The SNR values are improved by 3-9 dB. For measured data, wavelet de-noising method can also separate noise from useful signal and make late data smooth.
出处
《现代电子技术》
2013年第3期58-62,共5页
Modern Electronics Technique
基金
国家"十二五"重大专项(2011ZX05042-003-002):CO_2注入后的运移监测和安全技术研究
关键词
TEM信号
三点指数逼近非线性平滑去噪
ICA
小波分析
TEM signal
three-point exponential approximation nonlinear smooth denoising method
ICA
wavelet analysis
