台基观测方式对地震台站背景噪声影响分析  

Influence analysis of observation mode for seismic station on background noise

作　　者：杨亚运 汪建 傅卓 张巡 Yang Yayun;Wang Jian;Fu Zhuo;Zhang Xun(Chongqing Earthquake Agency,Chongqing 401147,China)

机构地区：[1]重庆市地震局,重庆401147

出　　处：《地震科学进展》2023年第6期241-250,共10页Progress in Earthquake Sciences

基　　金：中国地震局2022年三结合课题(3JH-202201001)资助。

摘　　要：重庆地区3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3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3个台站台基背景噪声变化情况。计算结果表明,3个改造台站环境噪声水平有所增加,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)最大增加10 dB,忠县善广台(SHG)最大增加4 dB。目前,3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。Three seismic stations in Chongqing area have been reconstructed.And the type of station base is changed from deep pit observation to surface observation.The PSD and PDF of the three stations before and after reconstruction were calculated respectively,and 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,the environmental noise level of the three reconstructed stations still increased,especially for frequency bands above 2 Hz.The maximum increase of PSD is 9 dB at YUM station,10 dB at LIJ station,and 4 dB at SHG station.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 we carry out the construction and reconstruction of seismic stations,it is necessary to carefully change the observation mode of the station base.

关 键 词：重庆地区 噪声功率谱密度 概率密度函数 环境噪声水平 

分 类 号：P315.61[天文地球—地震学]