准周期随机声脉冲序列信号海洋信道中远程传输特性

项目名称： 准周期随机声脉冲序列信号海洋信道中远程传输特性

项目编号： No.11474301

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 林建恒

作者单位： 中国科学院声学研究所

项目金额： 92万元

中文摘要： 实现海洋中船舶噪声远程微弱信号被动检测，必须研究掌握经过海洋信道远程传输后船舶噪声特征的变化。准周期随机声脉冲序列信号作为船舶噪声一种时域模型,从物理层面揭示,在大多数情况下船舶噪声本身并不直接含有任何正弦波分量，它所携带的正弦波信息需经非线性变换获得。本项目研究计算机仿真构建准周期随机声脉冲序列信号，理论分析、计算机模拟和海上试验研究它经过随机海洋信道传输后特性的变化，研究海洋信道多途和随机性、运动散射体多普勒等因素引起的频率选择性衰落和时间选择性衰落，对准周期随机声脉冲序列信号的作用；侧重探讨海洋信道的随机性对其准周期性和序列脉冲形状的作用，揭示远程传输后船舶噪声低频线谱产生额外衰减的本质原因。本项目还将采用周期性循环特征量来分析准周期随机声脉冲序列信号,探讨其循环高阶特征量在海洋信道传输后的变化。项目的研究结果将可为远程水下目标噪声微弱信号检测提供物理依据和技术基础。

中文关键词： 准周期；随机声脉冲序列；随机海洋信道；远程传输；船舶辐射噪声

英文摘要： To realize the passive detection of weak signals of ship noise in the ocean, the changes of ship noise characteristics caused by the long-distance transmission in ocean channel must be studied.As a time domain model of ship noise, quasi-periodic random sound pulse sequence signal has revealed from the physical meaning that, in most cases, the ship noise itself does not directly contain any sine wave, while the sine wave information carried by the pulse sequence signal must be obtained by nonlinear transformation.The quasi-periodic random sound pulse sequence signal will be built by computer simulation in this project,and its characteristics changes after random ocean channel transmission will be studied by theorecical analysis, computer simulation and experimental tests. The influence of frequency selective fading and time selective fading caused by multi-path, randomness and the Doppler effect of moving scatters in ocean channel on quasi-periodic random sound pulse sequence signal will be discussed, and the focus will be to study the effect of ocean channel randomness on the quasi-periodicity and sequence pulse shape, and revealing the essentil reason of the extra attenuation of ship noise low frequency line spectrums after long-distance transmission.This project will also use the periodic cycle statistics characteristics to analyze the quasi-periodic random sound pulse sequence signal, and discuss the change of its cyclic higher-order statistics characteristics after the transmission in ocean channel. The results of this project will provide a physical basis and technology foundation for the long-distance weak signal detection of underwater target.

英文关键词： quasi-periodicity;random sound pulse sequence;random ocean channel;long-distance transmission;ship radiation noise