基于最优阈值参考的瞬变电磁法小波降噪效果研究  

Study on wavelet denoising effect of transient electromagnetic method based on optimal threshold reference

作　　者：董毅 杨创 DONG Yi;YANG Chuang(China Coal Aerial Survey and Remote Sensing Group Co.,Ltd.,Xi’an 710100,China)

机构地区：[1]中煤航测遥感集团有限公司,陕西西安710100

出　　处：《煤矿安全》2024年第1期185-191,共7页Safety in Coal Mines

摘　　要：瞬变电磁法野外数据采集容易受各种随机干扰影响而出现跳变现象,小波去噪通过对信号的多尺度分解、阈值设置和重构,实现对数据的降噪。为进一步提高小波去噪后的瞬变电磁法数据质量,对该过程中的阈值选择方法进行改进,提出了基于最优阈值参考的小波去噪方法;结合瞬变电磁法探测岩层富水性工程应用,对比分析不同阈值条件下的数据降噪结果,提出的算法的瞬变电磁数据实际应用效果。结果显示:提出的方法能够进一步降低感应电动势曲线在1~4 ms范围内的数值跳变现象,使数据全期衰减特性更明显。对降噪后数据的烟圈反演结果进行分析,重点解释了3处电性差异相对较大的位置,结合已知资料验证了基于最优阈值参考的小波去噪数据反演结果相对更准确。The field data acquisition of transient electromagnetic method is prone to jump due to various random disturbances.Wavelet denoising realizes data denoising by multi-scale decomposition,threshold setting and reconstruction of signal.In order to improve the data quality of TEM after wavelet denoising,a new wavelet denoising method based on the optimal threshold reference is proposed to improve the threshold selection method.Combined with the application of transient electromagnetic method in waterrich engineering,the noise reduction results of data under different threshold conditions are compared and analyzed,and the practical application effect of the proposed algorithm is discussed.The results show that the proposed method can further reduce the value of the induced electromotive force curve in the range of 1-4 ms,and make the whole period attenuation characteristics of the data more obvious.The smoke ring inversion results of the denoised data were analyzed,and three locations with relatively large electrical differences were explained,and the inversion results of the denoised data based on the optimal threshold reference were verified to be more accurate.

关 键 词：瞬变电磁法 小波去噪 最优阈值 感应电动势曲线 烟圈反演 

分 类 号：TD745[矿业工程—矿井通风与安全]