地震计的改进型伪随机二进制标定方法  

Improved pseudo random binary calibration method for seismometers

作　　者：林湛[1] 薛兵[1] 朱小毅[1] 陈阳[1] 李江[1] 张妍[2] 彭朝勇[3] 

机构地区：[1]中国地震局地震预测研究所,北京100036 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国地震局地球物理研究所,北京100081

出　　处：《地球物理学进展》2015年第3期1151-1158,共8页Progress in Geophysics

基　　金：国家科技支撑项目课题"强震宽频带地震计研制"(2012BAF14B12-02)和国家科技支撑项目课题"低噪声超宽频带地震计研制"(2012BAF14B12-01)联合资助

摘　　要：地震计标定的一项重要内容是幅度响应的测量,一般采用电测法.目前,国内地震计应用者普遍采用阶跃标定或正弦标定的方法.本文提出了一种利用宽频带信号标定地震计的新方法:改进型伪随机二进制标定方法.在低频段,我们用伪随机二进制信号作为标定输入,在高频段,用一种新设计的信号作为标定输入.采用此方法,通过低频段和高频段两个测试实验可快速且准确的测量地震计在0.003 Hz到100 Hz上的幅度响应.实验分别耗时1048秒和204秒,幅度响应测试的频点间隔分别为0.0038Hz和0.49Hz.而且,标定信号形式简单,用简单的电路就可生成.通过与阶跃、正弦标定结果对比表明采用此方法测量地震计幅度响应时,其相对误差在小于2 Hz的频段上小于1%,在大于2 Hz的频段上小于2%.此方法与正弦标定相比,减少了实验耗时;与阶跃标定相比,增大了可测量的频带范围;与单纯利用伪随机二进制信号的方法相比,提高了在高频段测量结果的准确度.此外,其对幅度响应高频段宽度很窄的高峰的识别效果尤为显著.Electrical calibration can be used to get the amplitude response of the seismometer. Among Chinese seismometer users, the most widely used electrical calibration methods are sine calibration and step calibratioru In this paper, we introduce a new method to calibrate seismometers with broadband signals. We call it improved pseudo random binary calibration method. In low frequency band, we use pseudo random binary signal as calibration input. In high frequency band, we use a new designed signal as calibration input. With this method, one can test the amplitude response in the band between 0. 003 Hz to 100 Hz efficiently and accurately. This method includes two test experiments. The one for low frequency band test costs 1048 seconds and gets amplitude response values at frequencies with a 0. 0038 Hz interval. The one for high frequency band test costs 204 seconds and gets amplitude response values at frequencies with a 0. 49 Hz interval. The input signal has a very simple style, includes only two states. Therefore it can be generated by a very simple electronic circuit. With being compared to sine and step calibrations, we conclude that the relative error is less than 1~ in the band below 2 Hz and is less than 2% above 2 Hz. Compared to sine calibration, this method is time efficient. Compared to step calibration, it can test amplitude response in much broader band. Compared to method using only pseudo random binary signal, it can get more accurate results in high frequency band. And it is especially efficient when one uses it to detect narrow peaks of amplitude response in the high frequency band.

关 键 词：地震计 标定 宽频带 幅度响应 

分 类 号：P315[天文地球—地震学]