Welch参数的选择对台基噪声功率谱估计结果影响较大，目前尚无统一选取标准。通过比较不同Welch参数组合下功率谱密度曲线平滑度的变化规律，研究窗口长度和重叠率对功率谱估计的影响，并提出最低重叠率和匹配重叠率的概念。研究表明，当窗口长度大于50%、重叠率取值小于最低重叠率时，功率谱估计偏差较大；特定窗口长度对应一系列匹配重叠率，在匹配重叠率下的功率谱估计更准确。
The selection of Welch parameters has a significant impact on the estimation results of the power spectral density of seismic station noise, and there is currently no unified selection standard. By comparing the variations of the power spectral density curves smoothness at different Welch parameter combinations, this study investigates the effects of window length and overlap rate on power spectrum estimation, and introduces the concepts of minimum overlap rate and matching overlap rate. The result shows that when the window length is greater than 50%, and the overlap value is less than the minimum overlap, the bias in the power spectrum estimation is significant. A specific window length corresponds to a series of matching overlaps,and the power spectrum estimation under matching overlap is more accurate.
2023,44（4）: 63-67 收稿日期：2023-04-05
DOI：10.3969/j.issn.1003-3246.2023.04.010
基金项目：2021年河北省地方标准制修订项目计划（第二批）（项目编号：FW202154）
作者简介：尹康达(1987-),男,工程师,主要从事地震观测技术研究工作。E-mail:yinkangda@126.com
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