南京地震台甚宽频地震计观测性能研究  

Observation Performance of Very Broadband Seismometers at Nanjing Seismic Station

作　　者：张敏 宫杰[1] 立凯 张扬[1] 居海华[1] 胡光武 ZHANG Min;GONG Jie;LI Kai;ZHANG Yang;JU Haihua;HU Guangwu(Jiangsu Earthquake Agency,Nanjing 210014,China;Suqian Earthquake Monitoring Central Station,Suqian 222061,China;Nanjing Earthquake Monitoring Central Station,Nanjing 210014,China)

机构地区：[1]江苏省地震局,南京210014 [2]宿迁地震监测中心站,连云港222061 [3]南京地震监测中心站,南京210014

出　　处：《华南地震》2024年第3期51-58,共8页South China Journal of Seismology

基　　金：江苏省地震局青年科学基金项目(202206);中国地震局地震科技星火计划(XH21011)联合资助。

摘　　要：为深入研究甚宽频地震计观测性能,利用南京地震台GL-S120型和ITC-120A型两套甚宽频地震计开展对比观测。从台站记录波形、相关性以及台基噪声等方面开展差异性分析,结果表明:ITC-120A型地震计不易受外界干扰,尤其垂直向比较明显;两套地震计相关性夜晚安静时段优于白天;通过计算PSD(功率谱密度)分析台基噪声,结果表明GL-S120型地震计低频段噪声水平随着外界干扰增强而显著上升,导致GL-S120型地震计记录中小级远震效果较差,震相不易识别。自噪声计算分析表明两套地震计功率谱曲线差异与二者自噪声水平有关,检测方法和台基噪声等因素影响设备自噪声测试的相关性,从而影响地震计自噪声计算精度。In order to further study the observation performance of very broadband seismometers,two types of very broadband seismometers(GL-S120 and ITC-120A)at Nanjing Seismic Station were used to carry out comparative experiments.The difference analysis is carried out from the aspects of the waveform records at the station,correlation and ambient noise.The results indicate that ITC-120A is not susceptible to ambient interference,especially in the vertical direction.The correlation between the two seismometers at night is better than that in daytime.The ambient noise analysis by calculating power spectral density(PSD)illustrates that the noise level of GL-S120 in the low frequency band increases significantly with the increase in ambient interference,resulting in the poor effect in recording remote earthquakes of small to medium magnitudes by GL-S120 and difficult identification of seismic phase.The calculation and analysis of self-noise show that the difference in power spectrum curves of the two seismometers is related to their self-noise level.Factors such as detection methods and ambient noise have an impact on the correlation of equipment self-noise tests,thereby affecting the accuracy of seismometer self-noise calculation.

关 键 词：甚宽频地震计 自噪声 台基噪声 相关性 

分 类 号：P315.62[天文地球—地震学]