内蒙古地震烈度速报与预警工程基本站勘选仪器测试分析

Basic Station Selection and Instrument Analysis of Inner Mongolia Seismic Intensity Rapid Reporting and Early Warning Project

利用内蒙古地震烈度速报与预警工程10个基本站仪器勘选的加速度记录数据,选取每个测试点24小时稳定记录的仪器记录噪声数据,计算其各自噪声功率谱和加速度噪声有效值(a RMS),结合加速度地震计本身的频率特性和自噪声功率谱,综合分析了各个测试点的噪声水平和噪声功率谱分布特征,得出10个测试点都满足基本站最大背景振动加速度噪声均方根值的噪声水平要求,实测的各个场地噪声功率谱在0.003~3Hz,基本反映的是加速度仪器的自噪声。总的来看,测试使用的加速度计本身的自噪声水平还是比较高的,如果单纯以基本站的噪声水平作为基本要求,使用该加速度计作为勘选地噪声水平测试仪器是可以的,但要在1~20Hz频带范围上考虑多个频点的噪声水平使用该仪器是不能全面评价的。

24 hours stable acceleration noise data of 10 basic stations of Inner Mongolia seismic intensity rapid reporting and early warning project were used,the data comes from the accelerometer record.The noise power spectrum and the root mean square value of acceleration noise are calculated.Combined with the accelerometer's frequency characteristics and the self-noise power spectrum,the noise level and noise power spectrum distribution characteristics of each test point are analyzed comprehensively,it is concluded that the noise level requirements of the basic station is all satisfied by 10 test points,and the measured noise power spectrum of each site in the range of 0.003~3Hzfrequency band reflects the self-noise of the accelerometer.In general,the self-noise level of the accelerometer itself is relatively high,it is possible to use the accelerometer as a test instrument if the noise level of the basic station as the basic requirements.However,the noise level of multiple frequency points in the range of 1~20Hzfrequency band cannot be comprehensively evaluated using this instrument.