甚宽频带地震计噪声与环境耦合研究
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摘要
首先以甚宽频带地震计为研究对象,分析垂直向的片簧系统理论模型,探讨气压变化对仪器的LP噪声影响;通过理论分析,得出垂直向的片簧系统受气压变化影响较大。根据片簧系统的理论模型,设计一种密封安装方法,通过实验探讨地震计噪声与环境耦合关系(气压、温度和底座变形的关系)。最后对实验数据进行功率谱噪声分析,结果显示抽真空后地震计三个分向的噪声均降低,其中在100 s处垂直向、东西和南北向分别降低了10 dB、5 dB和6 dB。
In this study, the theoretical model of the vertical leaf spring system for very broadband seismometers was analyzed, and the influence of pressure changes on the LP noise of the instrument is discussed. The theoretical analysis showed that the vertical leaf spring system is quite affected by pressure changes. Then, according to the theoretical model of the leaf spring system, a kind of sealing installation method was designed, and the coupling relationship between the noise and the environment(pressure, temperature, and the base deformation) is discussed through experiments. Finally, the power spectrum noise analysis results of the experimental data showed that, after vacuuming, the noise in the three branch directions of the seismometer was reduced, at 100 s, by 10 dB, 5 dB, and 6 dB in the vertical direction, east-west direction, and north-south direction, respectively.
In this study, the theoretical model of the vertical leaf spring system for very broadband seismometers was analyzed, and the influence of pressure changes on the LP noise of the instrument is discussed. The theoretical analysis showed that the vertical leaf spring system is quite affected by pressure changes. Then, according to the theoretical model of the leaf spring system, a kind of sealing installation method was designed, and the coupling relationship between the noise and the environment(pressure, temperature, and the base deformation) is discussed through experiments. Finally, the power spectrum noise analysis results of the experimental data showed that, after vacuuming, the noise in the three branch directions of the seismometer was reduced, at 100 s, by 10 dB, 5 dB, and 6 dB in the vertical direction, east-west direction, and north-south direction, respectively.
引文
[1] 赵建和,张学应.Geotech宽频带数字地震观测系统原理及应用[J].地震地磁观测与研究,2004(b09):21-27.ZHAO Jianhe,ZHANG Xueying.Principle and Application of Geotech Broadband Digital Seismic Observation System[J].Seismological and Geomagnetic Observation and Research,2004(b09):21-27.
[2] 蔡亚先,吕永清,周云耀,等.CTS-1甚宽频带地震计[J].大地测量与地球动力学,2004,24(3):109-114CAI Yaxian,Lü Yongqing,ZHOU Yunyao,et al.CTS-1 Very Broadband Seismometer[ J] .Journal of Geodesy and Geodynamics .2004,24(3):109 -114.
[3] WIELANDT E.Seismic Sensors and their Calibration[M] .Chapter 5 of “ New Manual of Seismological Observatory Practice”.Geo Forschungs Zentrum Potsdam,2002.
[4] DIAZ J,VILLASENOR A,MORALES J,et al.Background Noise Characteristics at the Iber Array Broadband Seismic Network[J].Bull Seism Soc Amer,2010,100(2):618-628.
[5] JENS HAVSKOV,GERARDO ALGUACIL.Instrumentation in Earthquake Seismology[M].Beijing:Seismological Press,2007,6.
[6] WIELANDT,E.The Leaf-spring Seismometer:Design and Performance[J].Bulletin of the Seismological Society of America,1982,72(6A):2349-2367.
[7] 机械设计手册编委会.机械设计手册.第6卷[M].机械工业出版社,2004.Editorial Board of Mechanical Design Manual.Mechanical Design Manual.Volume 6[M].Mechanical Industry Press,2004.
[2] 蔡亚先,吕永清,周云耀,等.CTS-1甚宽频带地震计[J].大地测量与地球动力学,2004,24(3):109-114CAI Yaxian,Lü Yongqing,ZHOU Yunyao,et al.CTS-1 Very Broadband Seismometer[ J] .Journal of Geodesy and Geodynamics .2004,24(3):109 -114.
[3] WIELANDT E.Seismic Sensors and their Calibration[M] .Chapter 5 of “ New Manual of Seismological Observatory Practice”.Geo Forschungs Zentrum Potsdam,2002.
[4] DIAZ J,VILLASENOR A,MORALES J,et al.Background Noise Characteristics at the Iber Array Broadband Seismic Network[J].Bull Seism Soc Amer,2010,100(2):618-628.
[5] JENS HAVSKOV,GERARDO ALGUACIL.Instrumentation in Earthquake Seismology[M].Beijing:Seismological Press,2007,6.
[6] WIELANDT,E.The Leaf-spring Seismometer:Design and Performance[J].Bulletin of the Seismological Society of America,1982,72(6A):2349-2367.
[7] 机械设计手册编委会.机械设计手册.第6卷[M].机械工业出版社,2004.Editorial Board of Mechanical Design Manual.Mechanical Design Manual.Volume 6[M].Mechanical Industry Press,2004.