水中混响的混沌属性分析
Chaos characteristic analysis of underwater reverberation
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摘要: 用非线性动力学的理论方法分析实验水池混响、湖水混响以及海洋混响时间序列,以检验记录的混响过程是否能用低维非线性动力学建模,以及是否存在混沌属性。被分析数据采自不同的地理位置、不同的底质和水文环境,对应不同的声源,有一定的代表性。分析结果表明混响可在低至4维的动力学空间中展现不自交的动力学轨道,相近轨道按指数规律扩展或敛聚,其最大Lyapunov指数是正的且小于0.3。这个结果为混响的非线性动力学建模和基于混沌的非线性处理奠定基础。Abstract: Reverberation time series recorded in laboratory cistern, lake field and sea field have been examined by nonlinear dynamical methods, in order to identify chaos characteristic from its random-like waveform and to modeling them by low dimensions nonlinear dynamics. The data we analyzed are related to many geographic locations, bottom types, underwater conditions and transmitted signals. The results indicate that the reverberation can be modeled as 4-dimensions dynamical system with a positive maximum Lyapunov exponent (0 < λ1 < 0.3), so it may reveal a new approach based on chaos to process reverberation time series.