测震井下观测压制背景噪声特征分析

利用赤峰台井下和山洞观测、二连浩特台井下和地表观测测震数据，通过计算其加速度PSD值和相应的PDF值及1~20 Hz频段RMS值，研究井下观测压制测震台站背景噪声的特征。结果表明，在大于2 Hz频段，井下观测相比于山洞和地表观测有显著的压制背景噪声特征，尤其在大于9 Hz频段压制背景噪声特征突出；在16 s~2 Hz频段，井下、山洞、地表观测测震台站背景噪声水平一致性较高，井下观测在该频段不能压制背景噪声；在低于16 s频段，井下观测相比于山洞和地表观测有一定的压制背景噪声特征。通过井下观测可有效降低测震台站背景噪声水平，从而提高观测数据质量。

Inhibition of Background Noise by Underground Seismological Observation

By calculating RMS, PSD, and PDF value at 1 to 20 Hz band, the current study explores the suppressive effect on background noise, based on the comparison of underground, tunnel and surface seismological observed data from seismic stations Chifeng and Erenhot. The findings show that the underground observation has a significant suppressive effect of background noise in comparison with the tunnel and the surface over 2 Hz frequent bands, especially higher than 9 Hz frequent bands. The suppression of underground method would weaken when the frequency is less than 16 s. However, it disappears at 16 s to 2 Hz band. All three methods share a high level of coherence of background noise in the meantime. In conclusion, we can reduce background noise effectively through underground observation, so that the data quality will be optimized.