Analysis of that influence of the observation mode of seismic station on the background noise
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摘要: 重庆地区三个地震台站经改造后，台基类型由深坑观测改变为地表观测。分别计算三个台站改造前后的噪声功率谱密度（PSD）及相应的概率密度函数(PDF)，通过噪声功率谱平均噪声曲线，评估三个台站台基背景噪声变化情况。计算结果表明，虽受到2020年新冠肺炎疫情影响，台站背景噪声水平有所下降，但三个改造台站环境噪声水平却有所增加，尤其在2 Hz以上的频段，其中合川云门台（YUM）最大增加9 dB，开县临江台（LIJ）增加最大幅度为10 dB，忠县善广台（SHG）增大幅度为4 dB。目前，三个台站1—20 Hz频带范围内环境噪声水平仍符合观测规范要求，但改变台基观测方式后，传感器接收到人为干扰噪声信号更丰富。因此，开展地震台站建设、改造施工要慎重改变台基观测方式。Abstract: Three seismic stations in Chongqing area have been reconstructed, the type of station base is changed from deep pit observation to surface observation. The PSD and the PDF of the three stations before and after reconstruction were calculated respectively, the noise power spectrum is used to average the noise curve to evaluate the background noise variation of the three stations. The calculation results show that, excluding the impact of the epidemic situation of COVID-19 epidemic, the environmental noise level of the three reconstructed stations still increased, pecially in frequency bands above 2 Hz. The maximum increase of YUM Station is 9 dB, LIJ Station in is 10 dB, and SHG Station is 4 dB. But the overall environmental noise level between 1—20 Hz bands of the three stations still meets the requirements of the observation specifications. However, after changing the observation mode of the station base, the components of the noise signal received by the station change significantly, especially the human activity related noise, so when carry out the construction and reconstruction of seismic stations, it is necessary to carefully change the observation mode of the station base.
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图 1 台基改造台站及参考台站位置
Figure 1. Location of base reconstruction stations and reference station
图 2 XIM台和YUM台垂直分向功率谱概率密度函数分布图
Figure 2. Distribution of PDF of vertical split power spectrum of XIM Station and YUM Station
图 3 XIM台和YUM台各分向不同年份平均噪声功率谱曲线图
Figure 3. Average PSD in different years for each direction of XIM station and YUM station
图 4 LIJ台各分向改造前后功率谱概率密度函数分布图
Figure 4. Power Spectrum PDF Distribution of LIJ Station before and after Reconstruction
图 5 SHG台各分向改造前后功率谱概率密度函数分布图
Figure 5. PDF Distribution of SHG Station before and after Reconstruction
图 6 LIJ台和SHG台各分向改造前后平均噪声功率谱曲线图
Figure 6. Average PSD before and after Modification of LIJ station and SHG station
表 1 台站基本信息
Table 1. Information of the stations
台站名称 观测设备信息 地震计墩改造情况 改造日期 地震计型号 数采型号 频带范围 改造前相对
地面深度/m改造后相对
地面高度/m实际增加
高度/m合川云门台 DS-4A TD-324CI 2 s—50 Hz 3.0 0.5 3.5 2019.12.13 忠县善广台 DS-4A TD-324CI 2 s—50 Hz 4.0 0.3 4.3 2020.03.11 开县临江台 DS-4A TD-324CI 2 s—50 Hz 2.3 0.6 2.9 2020.03.17 垫江新民台 GL-S60 EDAS-24GN 60 s—50 Hz 3.0 0.5 3.5 未改造 
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[1] 杨亚运,傅卓,马伟. 地震计墩改造对观测数据影响分析[J]. 高原地震,2021,33(2):44-50,57 doi: 10.3969/j.issn.1005-586X.2021.02.008Yang Y Y,Fu Z,Ma W. Analysis of the influence of modified seismometer pier to observation data[J]. Plateau Earthquake Research,2021,33(2):44-50,57 doi: 10.3969/j.issn.1005-586X.2021.02.008 [2] 葛洪魁,陈海潮,欧阳飚,等. 流动地震观测背景噪声的台基响应[J]. 地球物理学报,2013,56(3):857-868 doi: 10.6038/cjg20130315Ge H K,Chen H C,Ouyang Biao,et al. Transportable seismometer response to seismic noise in vault[J]. Chinese Journal of Geophysics,2013,56(3):857-868 doi: 10.6038/cjg20130315 [3] Mcnamara D E,Buland R P. Ambient noise levels in the continental United States[J]. Bulletin of the Seismological Society of America,2004,94(4):1517-1527 doi: 10.1785/012003001 [4] Peterson J. Observations and modeling of seismic background noise[R]. Albuquerque: U. S. Geological Survey, 1993 [5] 廖诗荣,陈绯雯. 应用概率密度函数方法自动处理地震台站勘选测试数据[J]. 华南地震,2008,28(4):82-92 doi: 10.3969/j.issn.1001-8662.2008.04.010Liao S R,Chen F W. Automated seismic noise processing for seismic site selection using probability density functions method[J]. South China Earthquake,2008,28(4):82-92 doi: 10.3969/j.issn.1001-8662.2008.04.010 [6] 谢江涛,林丽萍,谌亮,等. 地震台站台基噪声功率谱概率密度函数Matlab实现[J]. 地震地磁观测与研究,2018,39(2):84-89 doi: 10.3969/j.issn.1003-3246.2018.02.012Xie J T,Lin L P,Chen L,et al. The program of probability density function of power spectral density curves from seismic noise of a station based on Matlab[J]. Seismological and Geomagnetic Observation and Research,2018,39(2):84-89 doi: 10.3969/j.issn.1003-3246.2018.02.012 [7] McNamara D E, Boaz R I. Seismic noise analysis system using power spectral density probability density functions: A stand-alone software package[R]. Reston, Virginia: U. S. Geological Survey, 2006: 1-29 [8] 吴建平,欧阳飚,王未来,等. 华北地区地震环境噪声特征研究[J]. 地震学报,2012,34(6):818-829 doi: 10.3969/j.issn.0253-3782.2012.06.008Wu J P,Ouyang B,Wang W L,et al. Ambient noise level of North China from temporary seismic array[J]. Acta Seismologica Sinica,2012,34(6):818-829 doi: 10.3969/j.issn.0253-3782.2012.06.008 [9] 巫立华,戴丽金,张丽娜,等. 地震台站勘选测试数据处理软件设计与应用[J]. 华南地震,2021,41(2):40-48 doi: 10.13512/j.hndz.2021.02.06Wu L H,Dai L J,Zhang L N,et al. Design and application of seismic noise processing software for seismic sit selection[J]. South China Journal of Seismology,2021,41(2):40-48 doi: 10.13512/j.hndz.2021.02.06 [10] 安全,赵艳红,郭延杰,等. 内蒙古山洞台站背景噪声特征分析[J]. 大地测量与动力学,2021,41(12):1312-1316An Q,Zhao Y H,Guo Y J,et al. Analysis of background noise characteristics of cave observation stations of Inner Mongolia seismic network[J]. Journal of Geodesy and Geodynamics,2021,41(12):1312-1316 [11] 立凯,陈浩,张朋,等. 江苏省测震台网背景噪声特征[J]. 华北地震科学,2021,39(3):66-71,76Li K,Chen H,Zhang P,et al. Background noise characteristics of Jiangsu seismological network[J]. North China Earthquake Sciences,2021,39(3):66-71,76 [12] 王芳, 王伟涛, 龙剑锋, 等. 中国大陆地区宽频带地震台网台基噪声特征[J]. 地震学报, 2019.41（5）: 569-584Wang F, Wang W T, Long J F, et al. Seismic noise characteristics of broad-band seismic networks in Chinese mainland[J]. Acta Seismologica Sinica. 2019, 41（ 5）: 569-584 -
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