运用Welch算法计算小泉沟地震台功率谱密度PSD，得到垂直向1/3倍频程带宽1—20 Hz各段的平均地动噪声RMS值为2.88×10-9 m/s，小于3.16×10-8 m/s，符合Ⅰ类台基标准。通过计算概率密度函数PDF，得到小泉沟地震台台背景噪声日变特征为，12—20时明显增大，夜间明显降低，背景噪声受人为活动影响较大；背景噪声年变特征受气温、气压影响较大，呈现夏低冬高的变化趋势。
Welch algorithm is used to calculate the power spectral density (PSD) of Xiaoquangou Seismic Station. The RMS value of the average ground motion noise is 2.88×10-9 ms for each section of the 1-20 Hz frequency band in the vertical direction of 1/3 octave, it is less than 3.16×10-8 m/s, which accords to class I standard. According to the calculated probability density function (PDF), the background noise of the Xiaoquangou Seismic Station is characterized by a significant increase in the background noise during the period from 12 to 20 o'clock and a significant decrease in the background noise at night. The annual variation of background noise was influenced by temperature and pressure, and showed a trend of low in summer and high in winter.
2024,45(1): 35-39 收稿日期：2023-04-23
DOI：10.3969/j.issn.1003-3246.2024.01.005
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