基于总体最小二乘-旋转不变算法的地表核磁共振信号参数估计  

Parameter Estimation of Surface Nuclear Magnetic Resonance Signals Based on Total Least Squares-Estimation of Signal Parameters via Rotational Invariance Technique

作　　者：于晓辉[1] 冯海 田宝凤[2] 孙海欣[3] 孙晓东[1] YU Xiaohui;FENG Hai;TIAN Baofeng;SUN Haixin;SUN Xiaodong(School of Communication Engineering,Jilin University,Changchun 130022,China;College of Instrumentation&Electrical Engineering/Key Laboratory of Geo-Exploration Instrumentation,Ministry of Education,Jilin University,Changchun 130026,China;School of Electronic and Information Engineering,Changchun University,Changchun 130022,China)

机构地区：[1]吉林大学通信工程学院,长春130022 [2]吉林大学仪器科学与电气工程学院/地球信息探测仪器教育部重点实验室,长春130026 [3]长春大学电子信息学院,长春130022

出　　处：《电子与信息学报》2024年第2期720-727,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(42074217)。

摘　　要：在地表核磁共振(SNMR)找水系统中,根据SNMR信号的参数能够预估地下含水层的储水量、导电性以及孔隙结构等信息。然而在实际应用中探测现场采集的SNMR信号十分微弱,易受到环境噪声干扰,导致无法直接获取SNMR信号的参数。针对这一问题,该文提出基于总体最小二乘-旋转不变法(TLS-ESPRIT)的地表核磁共振信号参数估计方法。基于谐波噪声与SNMR信号的相似信号特征构成一个由多个正弦衰减信号叠加的混合信号模型,使用TLS-ESPRIT将混合信号参数提取问题转换为旋转不变矩阵的广义特征值求解,从而获得SNMR信号的拉莫尔频率和弛豫时间,并结合最小二乘法求得其初始振幅和相位。仿真信号和实测信号实验结果表明此方法能够估计出混有随机噪声和工频谐波噪声的SNMR信号的参数,相比传统的谐波建模方法,在参数提取精度上效果更好。In the Surface Nuclear Magnetic Resonance(SNMR)water searching system,the parameters of SNMR signals can be used to predict the water storage,electrical conductivity,pore structure of underground aquifer.However,the SNMR signals collected on site are very weak in practical application,which is easy to be interfered by environmental noise,resulting in the inability to directly obtain the parameters of SNMR signal.To solve this problem,an estimation method of SNMR signal parameters based on Total Least Squares-Estimation of Signal Parameters via Rotational Invariance Technique(TLS-ESPRIT)is proposed in this paper.Based on the similar signal characteristics of harmonic noise and SNMR signals,a mixed signal model consisting of multiple sinusoidal attenuation signals is constructed.TLS-ESPRIT is used to transform the problem of extracting mixed signal parameters into a generalized eigenvalue solution of a rotation invariant matrix,in order to obtain the Lamor frequency and the relaxation time of the SNMR signal,and its initial amplitude and phase are obtained by combining the least squares method.The experimental results of simulated signal and measured signal show that the proposed method can estimate the parameters of SNMR signal mixed with random noise and power frequency harmonic noise.Compared with the traditional harmonic modeling method,the parameter extraction accuracy is better.

关 键 词：地表核磁共振 总体最小二乘-旋转不变法 谐波噪声 

分 类 号：P631[天文地球—地质矿产勘探]