基于混沌理论的舰船辐射噪声特征提取

摘要

针对不同目标舰船的辐射噪声信号特征提取问题，提出了将混沌理论用于非线性时间序列的分析方法。该方法利用非线性局部投影滤波方法进行信号降噪，并在重构相空间的基础上对每一类舰船辐射噪声信号的最大Lyapunov指数、自然测度和关联维数等非线性特征参数进行提取。实验结果表明：当舰船辐射噪声信号的最大Lyapunov指数大于0且为有限值时，舰船辐射噪声信号具有混沌特性；自然测度和关联维数可作为区分不同目标船型的舰船辐射噪声信号的有效特征。%An analysis method of nonlinear time-series based on chaos is proposed for the extraction of different ship-radiated noise characteristic parameters ,such as phase-space reconstruction and nonli-near local project noise reduction .T he method can be used to recover the origin signal and the phase trajectories effectively from the noise environment and to extract the nonlinear characteristic parame-ters of the maximum Lyapunov exponent , correlation dimension and natural measure of the ship-radiated signals on the basis of phase-space reconstruction .The experimental results show that ship-radiated noise is indeed chaotic because its largest Lyapunov exponent is positive ,and that both of cor-relation dimension and natural measure are regarded as the effective features of distinguishing the noise signals radiated form different types of ships .