利用山西地区垂直摆倾斜仪正常时段的观测数据，计算功率谱密度PSD和噪声水平SNM，对观测的正常背景特征进行分析和讨论。结果表明，未受任何干扰的观测数据每日PSD变化不大，分钟采样观测数据能反映最大为8.3 mHz的PSD分布，秒采样观测数据能反映最大为0.5 Hz的PSD分布。临汾地震台同址VS型、VP型垂直摆观测数据的噪声水平具有一致性；有2套仪器的背景噪声水平偏高，有4套仪器的背景噪声水平较低；低噪声水平仪器观测曲线光滑、固体潮清晰，运行稳定；高噪声水平仪器观测曲线毛刺多、不光滑。该现象除受观测环境影响以外，主要还受仪器自身的影响。
Using the observation data of the vertical pendulum tiltmeter in the normal period of Shanxi region, this study calculates the Power Spectral Density (PSD) and Signal-to-Noise Metric (SNM) to analyze and discuss the characteristics of the normal background observations. The results indicate that the daily PSD of undisturbed observation data does not vary significantly. Minute-sampling observation data can reflect a PSD distribution up to 8.3 mHz, while second-sampling observation data can reflect a PSD distribution up to 0.5 Hz. The noise levels of the VS and VP vertical pendulum observation data are consistent at the Linfen Station; two sets of instruments have higher background noise levels, while four sets have lower background noise levels. Instruments with lower noise levels produce smooth observation curves with clear solid tides and operate stably; instruments with higher noise levels have many spikes and are not smooth in their observation curves. The phenomenon is affected not only by the observation environment but also primarily by the instrument themselves.
2024,45(1): 101-107 收稿日期：2023-08-14
DOI：10.3969/j.issn.1003-3246.2024.01.014
基金项目：中国地震局监测、预报、科研三结合课题（项目编号：3JH-202301010）；山西省地震局青年项目（项目编号：SBK-2308）
参考文献：
韩宇飞,江颖,张晓彤,等. 陆态网络太原台gPhone重力仪背景噪声水平研究[J]. 大地测量与地球动力学,2015,35(5):898-900.
侯颉,余大新,叶庆东,等. 北京市测震台网数字地震台站台基背景噪声分析[J]. 地震地磁观测与研究,2019,40(4):102-107.
胡宝慧,刘双,常金龙,等. 黑龙江省地震科学台阵背景噪声特征分析[J]. 地震地磁观测与研究,2020,41(5):63-68.
徐义贤,罗银河. 噪声地震学方法及其应用[J]. 地球物理学报,2015,58(8):2 618-2 636.
张小艳,赵星,熊峰,等. 内蒙古地倾斜观测主要干扰信号的功率谱密度特征[J]. 华北地震科学,2022,40(3):62-68.
张小艳,赵星,熊峰,等. 内蒙古VP垂直摆倾斜仪背景噪声水平[J]. 华北地震科学,2023,41(2):108-112.
赵莹. VP垂直摆观测背景的功率谱密度特征分析[J]. 大地测量与地球动力学,2018,38(10):1 080-1 085,1 095.
赵莹. 全台网垂直摆倾斜仪背景噪声水平分析[J]. 大地测量与地球动力学,2019,39(8):869-874.
