题名 | 随机海洋中声传播的混沌分解方法 |
作者 | 邢皓 |
学位类别 | 博士 |
答辩日期 | 2008-05-30 |
授予单位 | 中国科学院声学研究所 |
授予地点 | 声学研究所 |
关键词 | 随机海洋环境 Wiener混沌 抛物方程 |
其他题名 | Sound Propagating in a Fluctuation Ocean - A Chaos Decomposition Approach |
学位专业 | 声学 |
中文摘要 | 随机起伏的海洋环境使得在其内部传播的声信号发生畸变,显著降低接收信号的时间和空间相干性,从而影响主被动声纳和水下通讯系统的性能,因此研究起伏海洋中的声传播规律有很高的理论价值和十分重要的军事应用价值,一直以来都是水声理论和实验研究的热点之一。本文在宽角度抛物方程(WAPE)的基础上,结合Wiener混沌分解方法,建立了一套完整的随机扰动处在下,海洋波导中的传播问题的求解方法,得到了描述该问题的偏微分方程组。该方法可适用于具有任意声速剖面的海洋环境,对随机扰动的概率分布也没有限制。同时,利用``隐式差分法''和``谱方法''等常用的数值计算手段,本文详细给出了数值求解该微分方程组的方法和具体步骤。随后,本文利用这套方法,研究了三种海洋环境下,两种类型的随机起伏对声场的平均声强、自协方差函数以及垂直相关性的影响。最后将数值计算的结果与黄海声传播与环境观测同步实验的数据进行了比较,发现两者具有较好的一致性,从而验证了模型的有效性。 |
英文摘要 | The random fluctuation of ocean environment can distort the underwater signals, which may significantly decrease the correlation of the signals received by hydrophones. It can affect the performances of sonar systems and underwater communication system. Thus, the study of sound propagation in random ocean is of great theoretical and practical importance. In this thesis, a set of partial differential equations, which based on the wide-angle parabolic equation and Wiener-chaos decomposition, was established to study the propagation of sound propagation in the ocean environment with arbitrary sound speed profile and stochastic perturbations with arbitrary probability density functions. Simultaneously, a numerical treatment of the PDEs, which employed implicit difference method and spectral method, was developed. Using the methods mentioned above, three cases with different kinds of randomness under distinct ocean environment are study numerically; and average sound intensity, auto-covariance functions and correlation function were calculated. Finally, a comparison between simulations and the data from the experiment was carried out which shows a consistency result. The model was thus validated. |
语种 | 中文 |
公开日期 | 2011-05-07 |
页码 | 69 |
内容类型 | 学位论文 |
源URL | [http://159.226.59.140/handle/311008/378] |
专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
推荐引用方式 GB/T 7714 | 邢皓. 随机海洋中声传播的混沌分解方法[D]. 声学研究所. 中国科学院声学研究所. 2008. |
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