摘要
为了进一步保留大地电磁低频段的有用信息、提高矿集区复杂噪声环境下大地电磁测深深部探测能力,在形态滤波的基础上结合信号子空间增强和端点检测做二次信噪分离处理.首先,针对形态滤波预提取的噪声轮廓运用信号子空间增强分离出信号子空间和噪声子空间.然后,将信号子空间和重构信号相结合并将噪声子空间置零.最后,借鉴端点检测做后处理,以识别波形突变的起止点.仿真结果表明,卡尼亚电阻率曲线在低频段的数据质量得到了明显改善、视电阻率值相对稳定;有效地补偿了形态滤波处理过程中损失的低频有用信号,其结果更加真实地反映了测点本身所固有的大地电磁深部构造信息.
To retain useful information of magnetotelluric low frequency band and improve the capacity of magnetotelluric deep detection in ore concentration area with complex noises,the combined signal subspace enhancement with endpoint detection is proposed based on morphology fltering to secondary signal-to-noise separation processing.Firstly,aimed at noise contour extracted by morphology fltering,we use signal subspace enhancement to separate signal subspace and noise subspace for pretreatment.Secondly,the signal subspace is combined with reconstructed signal and the noise subspace is set to zero.Finally,endpoint detection for post-processing is carried out in order to identify the start and end points of the waveform mutation.Simulated results show that Cagniard resistivity curve in the low frequency band has been improved obviously,and the apparent resistivity value is relatively stable.The proposed method is better to ofset the loss of low frequency useful information in the process of the morphological fltering,and the results can even more truly refect the inherent deep structural information of low frequency components for the measured point itself.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第1期414-423,共10页
Acta Physica Sinica
基金
国家科技专项"深部探测技术与实验研究"(批准号:SinoProbe-03)
国家自然科学基金(批准号:41104071)
湖南师范大学博士基金(批准号:130617)资助的课题~~
关键词
大地电磁
噪声压制
信号子空间增强
端点检测
magnetotelluric sounding data
noise suppression
signal subspace enhancement
endpoint detection
