基于同步挤压S变换的探地雷达信号消噪方法
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摘要
为提高对探地雷达低幅度有用信号的识别效果,提出了基于同步挤压S变换的消噪方法.首先将含噪声信号进行S变换,并计算出信号的瞬时频率,再将信号的时频能量进行重新集中,从而获得高分辨率的压缩时频谱.然后根据噪声出现的时间和频率,设计相应的二维滤波器在时频域对信号进行消噪.在消除噪声能量后,再进行反变换得到有用信号.由于在压缩时频谱上可以更好地区分有用信号和噪声,消噪时有效信号的能量可以被尽可能多地保留下来.仿真信号和探地雷达实际信号的处理结果表明,利用同步挤压S变换在时频域进行消噪能够取得很好的效果.
In order to better identify useful low-amplitude ground penetrating radar(GPR)signals,a de-noising method based on the synchrosqueezing S-transform(SSST)is proposed in this paper. Firstly,the new method performs S-transform onto a signal containing noise,calculates instantaneous frequencies of the signal,and relocates the energy of the signal to vicinity of the instantaneous frequencies to obtain high resolution compressed time-frequency spectrum. Then,according to the time and frequency coordinates of the noise,two-dimensional filters are designed to remove noise from the signal in the T-F domain. After the noise being removed,the useful signal can be restored after performing inverse transform on the T-F spectrum. Since the energy of the useful signal and the noise can be more clearly distinguished on the compressed T-F spectrum,the energy of the useful signal would be better retained. The processing results of a simulated signal and GPR data show that the T-F domain de-noising method using SSST can obtain better results than using the conventional T-F transforms.
In order to better identify useful low-amplitude ground penetrating radar(GPR)signals,a de-noising method based on the synchrosqueezing S-transform(SSST)is proposed in this paper. Firstly,the new method performs S-transform onto a signal containing noise,calculates instantaneous frequencies of the signal,and relocates the energy of the signal to vicinity of the instantaneous frequencies to obtain high resolution compressed time-frequency spectrum. Then,according to the time and frequency coordinates of the noise,two-dimensional filters are designed to remove noise from the signal in the T-F domain. After the noise being removed,the useful signal can be restored after performing inverse transform on the T-F spectrum. Since the energy of the useful signal and the noise can be more clearly distinguished on the compressed T-F spectrum,the energy of the useful signal would be better retained. The processing results of a simulated signal and GPR data show that the T-F domain de-noising method using SSST can obtain better results than using the conventional T-F transforms.
引文
[1]汤井田,唐晋,肖晓.瞬时参数在探地雷达公路路基隐患排查中的应用[J].物探化探计算技术,2017,39(2):211-218.
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[10]张超.微弱地震信号时频消噪算法研究[D].长春:吉林大学,2016.
[11]吴楠,吴舰,吴志坚.探地雷达信号消噪中的时频谱分解重排算法[J].物探与化探,2018,42(1):220-224.
[12]Daubechies I,Lu J,Wu H T.Synchrosqueezed wavelet transforms:An empirical mode decomposition-like tool[J].Applied&Computational Harmonic Analysis,2011,30(2):243-261.
[13]黄忠来,张建中.同步挤压S变换[J].中国科学:信息科学,2016,46(5):643-650.
[14]Huang Z L,Zhang J Z.Synchrosqueezing S-transform and its application in seismic spectral decomposition[J].IEEE Transactions on Geoscience and Remote Sensing,2016,54(2):817-825.
[2]朱楠男,李家存,叶培盛.探地雷达在古墓遗址探测中的应用:以北京市通州区古墓群探测为例[J].物探与化探,2017,41(3):577-582.
[3]郝士华,娄国充.探地雷达在岩溶公路隧道地区超前探测技术研究[J].公路工程,2017,42(4):285-289.
[4]魏晓杰,刘亚克.探地雷达在浅层管道探测中的应用[J].现代测绘,2017,40(3):38-41.
[5]Takahashi K,Preetz H,Igel J.Soil properties and performance of landmine detection by metal detector and ground penetrating radar:Soil characterization and its verification by a field test[J].Journal of Applied Geophysics,2011,73(4):368-377.
[6]汪文强,刘争平,白国东,等.探地雷达在地铁盾构施工滞后沉降监测中的应用研究[J].地球物理学进展,2016,31(1):354-359.
[7]任政委,查恩来,龙慧,等.中国南极科学考察探地雷达海冰探测[J].地球物理学进展,2017,32(2):898-901.
[8]戴前伟,吴铠均,张彬.短时傅里叶变换在GPR数据解释中的应用[J].物探与化探,2016,40(6):1227-1231.
[9]王超,沈斐敏.小波变换在探地雷达弱信号去噪中的研究[J].物探与化探,2015,39(2):421-424.
[10]张超.微弱地震信号时频消噪算法研究[D].长春:吉林大学,2016.
[11]吴楠,吴舰,吴志坚.探地雷达信号消噪中的时频谱分解重排算法[J].物探与化探,2018,42(1):220-224.
[12]Daubechies I,Lu J,Wu H T.Synchrosqueezed wavelet transforms:An empirical mode decomposition-like tool[J].Applied&Computational Harmonic Analysis,2011,30(2):243-261.
[13]黄忠来,张建中.同步挤压S变换[J].中国科学:信息科学,2016,46(5):643-650.
[14]Huang Z L,Zhang J Z.Synchrosqueezing S-transform and its application in seismic spectral decomposition[J].IEEE Transactions on Geoscience and Remote Sensing,2016,54(2):817-825.