北京测震台网台基背景噪声特征

利用Welch算法,选取北京市测震台网28个测震台站地震连续波形中不同时段的无震记录,计算其台基噪声功率谱并进行背景噪声特征的统计分析,结果表明:北京市测震台网各台基噪声背景优势频率各有特征,高低频段噪声功率谱曲线差异大。在1~20Hz频段内,北京地区的背景噪声高值区出现在中心城区附近,低值区出现在北部的琉璃庙、密云和南部的上方山等台站,主要受人为噪声影响;在0.008~0.1Hz频段内,北京所有地区差异不大。

Background Noise Characteristics of Beijing Seismic Network

Using the Welch algorithm, the different time periods’ earthquake-free records of the continuous three-component seismometer waveform of 28 seismic stations in Beijing Seismic Network were selected, the power spectrum density of the base-based noise was calculated and statistically analyzed.The results show that the dominant frequency of each base noise background of Beijing Seismic Network has its own characteristics, and the difference between the high and low frequency noise power spectrum curves is large.In the 1~20 Hz frequency band, the high value area of the background noise value in Beijing appears near the central city, and the low value area appears in Liulimiao and Miyun in the north, and Shangfangshan in the south, which is mainly affected by man-made noise.In the frequency range of 0.008~0.1 Hz, there is little difference in all areas of Beijing.