关于地震观测系统中滤波器的讨论  

Discussion on Filters in Earthquake Observation Instruments

作　　者：薛兵[1] XUE Bing(Institute of Earthquake Forecasting,CEA,Beijing 100036,China)

机构地区：[1]中国地震局地震预测研究所,北京100036

出　　处：《地震》2021年第1期40-50,共11页Earthquake

基　　金：国家重点研发计划课题(2018YFC1503904);地震预测研究所基本科研业务费专项(2020IEF1202)。

摘　　要：用于定点连续观测的地震观测仪器,产出的观测数据是一个时间序列,反映了被观测量随时间的变化。本文将地震观测系统中任何与频率特性有关的信号处理过程均视为滤波器,如传感器的频率特性、数据采集过程中的抗混叠滤波等,对地震观测系统中的滤波器进行了深入讨论。实际工作中往往认为慢变量信号中不存在高频分量,使得在数据采集过程中忽视了抗混叠滤波器的应用,从而在实际观测中导致频率混叠干扰时有发生。针对这一问题,本文通过模拟计算的示例,显示了频率混叠干扰对观测数据质量的影响,解释了分量应变分钟值观测数据中同震响应波形的不合理现象,进一步阐明了数据采集过程中抗混叠滤波器的重要作用。The data output by earthquake observing instruments installed at fixed stations is a time series,which reflects the changes of the observed object over time.In this case,it is very important to understand the frequency response of the instrument.This article regards any signal processing process related to frequency response as filters,such as filters related to the frequency response of the sensor,anti-aliasing filters in the data acquisition process,etc.,and discusses carefully.In some cases,the anti-aliasing filter is ignored,because the observation object changes slowly with time,and it is considered that there is almost no high-frequency component.However,this understanding is incorrect,and frequency aliasing interference is often found in actual observations.A simulation calculation example is used to illustrate the influence of frequency aliasing interference on the observation data,to explain the unreasonable phenomenon of the coseismic waveform in the component strain observation.

关 键 词：地震观测仪器 滤波器 频率特性 

分 类 号：P315.7[天文地球—地震学]