Seismic Exploration Random Noise on Land: Modeling and Application to Noise Suppression
Seismic Exploration Random Noise on Land: Modeling and Application to Noise Suppression
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DOI：
10.1109/tgrs.2017.2697444
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发表时间：
2017-05
影响因子：
8.2
通讯作者：
Guanghui Li;Yue Li;Baojun Yang
中科院分区：
文献类型：
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作者：
Guanghui Li;Yue Li;Baojun Yang
在地震勘探中，随机噪声的压制是地震资料处理的关键问题之一。对于随机噪声衰减，最重要的是对地震随机噪声产生和传播的认识。地震随机噪声被认为是时间和空间随机过程，由于其高度变异性，目前只能定性分析。本文对地震随机噪声源按产生因素进行了分类，并对中国西部沙漠地区的随机噪声进行了模拟。根据绿色函数，可以假定地震随机噪声源是分布在检波器周围的点状源。将地震随机噪声记录视为均匀各向同性半无限表面上所有独立震源激发的叠加波场。根据风振理论和对环境振动的初步研究，确定了噪声源函数。通过求解非齐次波动方程，得到了各种噪声的波形，并对其特性进行了定性和定量分析。得到了时间为1.6 s、距离为250 m的合成地震记录，并分别在时间域和空间域上比较了模拟记录与真实的噪声记录的特征。对比结果表明，仿真噪声与真实的噪声具有相同的特性，验证了该方法的可行性。通过噪声建模可知，近场文化噪声是沙漠中随机噪声的主要成分，在此基础上选择了复扩散滤波。将复扩散滤波的滤波结果与近年来流行的地震随机噪声压制滤波方法时频峰值滤波的结果进行了比较。比较结果表明，复扩散滤波更适合于塔里木盆地沙漠地区的噪声。这一结果证明，地震随机噪声建模可以为噪声衰减提供指导。为今后研究地震随机噪声的传播特性和更好地衰减奠定了基础。
In seismic exploration, random noise suppression is one of the key problems in seismic data processing. For random noise attenuation, the most important thing is the understanding of seismic random noise generation and propagation. Seismic random noise is considered as temporal and spatial random processes, and it can be analyzed only qualitatively for now, due to its high variability. In this paper, we classify seismic random noise sources by their generation factors and simulate the random noise of the desert in West China. According to Green’s function, it can be assumed that seismic random noise sources are point-like sources that are distributed around geophones. A seismic random noise record is taken as the superimposed wave field exited by all the independent sources in a homogeneous isotropy half-infinite surface. Based on the wind vibration theory and preliminary study about ambient vibrations, the noise source functions are determined. We obtain the waveforms of different kinds of noise by solving the inhomogeneous wave equations and analyze the characteristics qualitatively and quantitatively. The seismic synthetic record with a 1.6-s time and 250-m distances is obtained, and the characteristics are compared between the simulated and the real noise record in time domain and space domain, respectively. The comparative results show the same characteristics of the simulated noise and the real noise, which demonstrates the feasibility of the proposed method. According to the noise modeling, it is known that the near-field cultural noise is the main component of the random noise in the desert, on the basis of which complex diffusion filtering is selected. The filtered results by complex diffusion filtering is compared with the results of time–frequency peak filtering, which is a popular filtering method of seismic random noise suppression in recent years. The comparative results show that complex diffusion filtering is more suitable for the noise of the desert in the Tarim Basin. This result proves that seismic random noise modeling can provide the guidance for noise attenuation. It lays a foundation for researching the propagation characteristics and better attenuation of seismic random noise in the future.