向家坝数字遥测地震台网的台基地噪声分析

Analysis on the background noise of Xiangjiaba digital telemetered seismic network

目前,国内大多数地噪声功率谱计算程序得到的都是加速度坐标系下的结果,且最高计算频率仅为20Hz,而我国数字地震观测普遍使用速度平坦型特性,从计算上来考虑,使用速度坐标系绘制地噪声功率谱曲线更直观。另外,由于水库诱发地震观测将其频带上限扩展至40 Hz,台址地噪声分析频带也需要作相应的扩展。本文作者在向家坝数字遥测地震台网台址勘选数据的分析处理中,结合水库诱发地震监测的需要,编写了地动速度功率谱密度计算程序,计算出了勘选台站的功率谱密度及(1/3)倍频程1～40 Hz带宽的均方根值。

Currently, most of the result in the acceleration However, in our country, velocity coordinate system addition, upper frequency available software for ground noise power spectrum can get the coordinate system, and with the highest frequency of 20 Hz. digital seismic networks prefer to use velocity response. So using to plot ground noise power spectrum curve is more nature. In limit of reservoir induced earthquake is extended to 40 Hz, therefore the analysis frequency band of ground noise should be extended. In the process of analysis on the background noise of Xiangjiaba network, the author encodes the software of ground velocity power spectral density, which calculates power density spectrum and Root- Mean-Square（rms） of third-octave 1-40 Hz band of all stations.