陆地地震勘探环境噪声的混沌性建模研究

为提取地震资料中的有效信息, 了解环境噪声的性质和产生机制, 提出了一种陆地地震勘探环境噪声的混沌建模方法。该类环境噪声具有混沌性出发, 采用经典混沌杜芬(Duffing)系统对中国林带测区的环境噪声进行建模。根据Duffing 系统的非线性特征, 采用MCMC(Markov Chain Monte Carlo)算法对系统参数进行求解,并对模拟噪声记录与实际环境噪声从时域波形, 相态图, 频谱图以及李雅谱诺夫(Lyapunov)指数等方面进行对比分析。结果表明, 模拟噪声记录可保持实际环境噪声的混沌性, 且在时域波形, 相态图和频谱图上拟合较好。利用此模型获得的替代数据更加接近实际噪声, 从而为压制环境噪声提供新对策, 为复杂环境下的地震勘探提供理论支持。

Modeling Study of Chaotic Ambient Noise in Land Seismic Exploration

Actual seismic exploration is corrupted by a variety of random noise. It is necessary to eliminate noise to extract the valid data. To address modeling method of ambient noise in land seismic exploration, this paper used classical chaotic Duffing system to model the ambient noise of forest belt area in China according to chaos of the ambient noise. It used MCMC(Markov Chain Monte Carlo) method to solve the system parameters according to nonlinear characteristics of Duffing system, and it contrasted simulated noise with actual ambient noise in terms of time-domain waveform, phase diagram, spectrum and Lyapunov exponent. The results show that the simulated noise records keep the chaos of the actual ambient noise, and the two noise have a good curve fitting in terms of time-domain waveform, phase diagram, spectrum. Therefore, the use of the Duffing system for land seismic ambient noise has certain prospects. The surrogate data obtained by the Duffing system is closer to the actual noise, which can provide new strategies to suppress noise and theoretical supports for seismic exploration in complex environment.