台网噪声评估及其对气枪震源激发效果影响的研究

发布时间：2018-07-12 17:46

本文选题：噪声水平 + 气枪震源　；参考：《地震学报》2017年03期

【摘要】：为了研究背景噪声对长江地学气枪主动源实验激发效果的影响,收集了240个台站激发前72小时的背景噪声数据及20个定点激发的叠加结果进行实验分析.先剔除异常台站,按照国标将台网噪声水平划分为高、中、低3个等级进行评估,从而研究气枪波形信噪比与台站背景噪声的关系.结果表明:(1)台站接收能力与背景噪声水平密切相关;(2)气枪信号的信噪比在一定范围内受背景噪声的影响大于距离衰减的影响;(3)长江马鞍山—安庆流域段不同定点激发的场地条件基本一致;(4)随气枪信号叠加次数的增加,低噪台站的信噪比增长速度快于中、高噪台站,若想获得同样的叠加效果,高噪台站需要的叠加次数远大于低噪台站.
[Abstract]:In order to study the effect of background noise on the experimental excitation effect of active source of Changjiang Geoscience Air Gun, the background noise data of 240 stations and the superposition results of 20 fixed points excitation were collected and analyzed experimentally. The noise level of the station is divided into three grades: high, middle and low according to the national standard, and the relation between the signal to noise ratio of the air gun waveform and the background noise of the station is studied. The results show that: (1) the receiving capacity of the station is closely related to the background noise level; (2) the SNR of the air gun signal is more affected by the background noise than the distance attenuation in a certain range; (3) the different fixed points in the Maanshan-Anqing watershed of the Yangtze River are affected by the SNR of the air gun signal. (4) with the increase of the number of superposition of the air gun signal, The signal-to-noise ratio (SNR) of low noise stations increases faster than that of medium noise stations. In order to obtain the same superposition effect, the high noise stations need far more stacking times than the low noise stations.
【作者单位】：福州大学土木工程学院;福建省地震局;
【基金】：国家自然科学基金(41474071) 地震行业科研专项(2015419015)共同资助
【分类号】：P315.7

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