WAN Ling,
ZHANG Yang,
LIN Jun et al
.2016.Spikes removal of magnetic resonance sounding data based on energy calculation.Chinese Journal Of Geophysics,59(6): 2290-2301,doi: 10.6038/cjg20160631
基于能量运算的磁共振信号尖峰噪声抑制方法
万玲, 张扬, 林君, 蒋川东, 林婷婷
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
Spikes removal of magnetic resonance sounding data based on energy calculation
WAN Ling, ZHANG Yang, LIN Jun, JIANG Chuan-Dong, LIN Ting-Ting
College of Instrumentation and Electrical Engineering/Key Laboratory of Geo-Exploration and Instrumentation, Ministry of Education, Jilin University, Changchun 130026, China
Abstract:Magnetic Resonance Sounding (MRS) signal is extremely easy corrupted by the noise, especially by the harmonic noise and spike noise. Harmonic noise cancellation is often based on remote references and the adaptive noise cancellation(ANC)algorithm to increase the signal-to-noise ratio (SNR). However, ANC algorithm cannot play an effective role when spike noise exists. Because the spike noise often lead to a bad correlation between the detection loop and the remote reference loop, it is necessary to remove the spike noise before using the adaptive noise cancellation algorithm to cancel the harmonic noise.#br#In the present paper, we provide a detailed insight into the technique of spike noise cancellation based on transferring the signal from time domain to energy domain and using the median absolute deviation method (MAD). First, we calculate the energy of MRS signal. After doing this, the signal is emphasized which is much more clear than in time domain. Then, a threshold principle based on MAD is provided to cancel all the noise above it.#br#In addition, this paper contains a comparison of the spike noise cancellation effects of Statistical Stacking and Energy cancellation. It is found that the two methods provide identical noise cancellation performance when the spike noise is strong and long enough. Statistical Stacking method is limited when the spike noise get weaker, especially weaker than 1.5 times of the signal. But Energy cancellation we proposed can still remove the spike noise and keep the MRS signal effectively. Moreover, from the noise properties analysis, correlation between the detection loop and the reference loop can be improved after spike noise cancellation. We first apply it on the synthetic data to see the correlation improvement and find that the correlation is improved from 0.1369 to 0.4941 after using the Energy cancellation.Then we obtain the true field data using the multi-channel MRS instrument in Changchun suburb, and apply the Energy cancellation method on the field data. The correlation is improved from 0.1575 to 0.2481. We also find that the harmonic noise is much more evident after spike noise cancellation, which is advantageous to use the adaptive noise cancellation later.#br#We anticipate that better noise cancelling results can be obtained with the Energy cancellation and adaptive noise cancellation methods used together and therefore a wider application of multi-channel MRS instrument can be made in future.
Fabian N. 2010. Processing of full time series, multichannel surface NMR signals[Master's thesis]. Switzerland: ETH Zürich. Hoaglin D C, Mosteller F, Tukey J W. 2000. Understanding Robust and Exploratory Data Analysis. New York: Wiley. Jiang C D, Lin J, Duan Q M, et al. 2011. Statistical stacking and adaptive notch filter to remove high-level electromagnetic noise from MRS measurements. Near Surf. Geophys., 9(5): 459-468. Legchenko A, Valla P. 2002. A review of the basic principles for proton magnetic resonance sounding measurements. J. Appl. Geophys., 50(1-2): 3-19. Legchenko A, Baltassat J M, Beauce A, et al. 2002. Nuclear magnetic resonance as a geophysical tool for hydrogeologists. J. Appl. Geophys., 50(1-2): 21-46. Lin J, Duan Q M, Wang Y J, et al. 2010. Theory and Design of Magnetic Resonance Sounding Instrument for Groundwater Detection and Its Applications (in Chinese). Beijing: Science Press. Lin J. 2010. Situation and progress of nuclear magnetic resonance technique for groundwater investigations. Progress in Geophysics (in Chinese), 25(2): 681-691, doi: 10.3969/j.issn.1004-2903.2010.02.043. Lin J, Jiang C D, Duan Q M, et al. 2012. The situation and progress of magnetic resonance sounding for groundwater investigations and underground applications. Journal of Jilin University (Earth Science Edition) (in Chinese), 42(5): 1560-1570. Lu Q H, Wu T B, Lin J. 2009. A research report on development of instrument science for geophysics. Progress in Geophysics (in Chinese), 24(2): 750-758. Lubczynski M, Roy J. 2003. Hydrogeological interpretation and potential of the new magnetic resonance sounding (MRS) method. Journal of Hydrology, 283(1-4): 19-40. Mukhopadhyay S, Ray G C. 1998. A new interpretation of nonlinear energy operator and its efficacy in spike detection. IEEE T. Biomed. Eng., 45(2): 180-187. Müller-Petke M, Yaramanci U. 2010. Improving the signal-to-noise ratio of surface-NMR measurements by reference channel based noise cancellation.//16th EAGE European Meeting of Environmental and Engineering Geophysics. EAGE. Müller-Petke M, Yaramanci U. 2011a. Noise Cancellation for surface NMR: Derivation of time and frequency domain approaches.//17th EAGE European Meeting of Environmental and Engineering Geophysics. EAGE. Müller-Petke M, Yaramanci U. 2011b. Noise cancellation for surface NMR-application of time and frequency domain approaches.//17th EAGE European Meeting of Environmental and Engineering Geophysics. EAGE. Miller D C. 1937. Sound Waves: Their Shape and Speed. New York: Macmillan Company Press. Pan Y L, Zhang C D. 2000. Theories and Methods of Surface Nuclear Magnetic Resonance (in Chinese). Beijing: China University of Geosciences Press. Radic T. 2006. Improving the signal-to-noise ratio of surface NMR data due to the remote reference technique.//12th EAGE European Meeting of Environmental and Engineering Geophysics. EAGE. Roy J, Lubczynski M. 2003. The magnetic resonance sounding technique and its use for groundwater investigations. Hydrogeol. J., 11(4): 455-465. Schirov M, Legchenko A, Creer G. 1991. A new direct non-invasive groundwater detection technology for Australia. Exploration Geophysics, 22(2): 333-338. Strehl S. 2006. Development of strategies for improved filtering and fitting of SNMR-signals. Germany: Technical University of Berlin, Institute of Applied Geosciences, Department of Applied Geophysics. Strehl S, Rommel I, Hertrich M, et al. 2006. New strategies for filtering and fitting of MRS signals.//Proceedings 3rd International MRS Workshop. Madrid, Spain, 65-68. Tian B F, Lin J, Duan Q M, et al. 2012. Variable step adaptive noise cancellation algorithm for magnetic resonance sounding signal with a reference coil. Chinese J. Geophys. (in Chinese), 55(7): 2462-2472, doi: 10.6038/j.issn.0001-5733.2012.07.030. Walsh D O. 2008. Multi-channel surface NMR instrumentation and software for 1D/2D groundwater investigations. J. Appl. Geophys., 66(3-4): 140-150. Wang Z X, Rong L L, Lin J. 2009. Spike noise elimination from surface nuclear magnetic resonance signal for underground water. Journal of Jilin University (Engineering and Technology Edition) (in Chinese), 39(5): 1282-1287. Wu S L, Zhang Q. 2010. Error Analysis and Data Processing (in Chinese). Beijing: Tsinghua University Press. Zhang R, Hu X Y, Yang D K, et al. 2006. Review of development of surface nuclear magnetic resonance. Progress in Geophysics (in Chinese), 21(1): 284-289. 附中文参考文献 林君, 段清明, 王应吉等. 2010. 核磁共振找水仪原理与应用. 北京: 科学出版社. 林君. 2010. 核磁共振找水技术的研究现状与发展趋势. 地球物理学进展, 25(2): 681-691, doi: 10.3969/j.issn.1004-2903.2010.02.043. 林君, 蒋川东, 段清明等. 2012. 复杂条件下地下水磁共振探测与灾害水源探查研究进展. 吉林大学学报(地球科学版), 42(5): 1560-1570. 陆其鹄, 吴天彪, 林君. 2009. 地球物理仪器学科发展研究报告. 地球物理学进展, 24(2): 750-758. 潘玉玲, 张昌达. 2000. 地面核磁共振找水理论和方法. 北京: 中国地质大学出版社. 田宝凤, 林君, 段清明等. 2012. 基于参考线圈和变步长自适应的磁共振信号噪声压制方法. 地球物理学报, 55(7): 2462-2472, doi: 10.6038/j.issn.0001-5733.2012.07.030. 王中兴, 荣亮亮, 林君. 2009. 地面核磁共振找水信号中的奇异干扰抑制. 吉林大学学报(工学版), 39(5): 1282-1287. 吴石林, 张玘. 2010. 误差分析与数据处理. 北京: 清华大学出版社. 张荣, 胡祥云, 杨迪琨等. 2006. 地面核磁共振技术发展述评. 地球物理学进展, 21(1): 284-289.