主动声呐目标回波信号建模技术

Modeling Technology for Active Sonar Target Echo Signal

利用声呐目标模拟信号对声呐系统进行性能分析是目前普遍采用的措施。根据实际需求,结合主动声呐回波信号产生机理开展精细化建模,根据声呐工作平台参数设计发射信号,模拟平台自噪声信号;考虑海况等级、海面与海底散射强度等边界条件模拟环境噪声和海洋混响;依据海水密度、水中声速和海底底质等传播条件模拟声场,通过信号级模拟设计了主动声呐目标信号。主动声呐目标信号包含平台自噪声、海洋环境噪声、混响和目标回波等信号。根据海面和海底混响理论模拟生成混响信号,基于目标散射声场理论和水下目标亮点模型模拟水下目标回波。仿真结果表明,该方法可准确模拟主动声呐回波基本特性,在理论研究和声呐系统性能分析领域具有重要意义。

The performance analysis of a sonar system by using sonar target analog signals is a com⁃monly used measure.According to the actual demands,and combined with a mechanism of an active sonar echo signal,the refined modeling is carried out.According to the parameters of the sonar work⁃ing platform,the transmitting signal is designed to simulate the platform self-noise signal.Considering the level of the boundary conditions,such as the sea state and the scattering intensity of sea surface and seafloor,the environment noise and the reverberation are simulated.The acoustic field is simulat⁃ed according to the propagation conditions,such as sea water density,sound velocity in water and sea⁃bed bottom,the active sonar target signal is designed by the signal level simulation.The active sonar target signals include platform self-noise,marine environmental noise,reverberation,and target echo,etc.Based on the theory of the sea surface and the seabed reverberation,the reverberation sig⁃nal is generated,and the underwater target echo is simulated based on the target scattering sound field theory and the underwater target bright spot model.Simulation results show that the active sonar tar⁃get signal method can accurately simulate the basic characteristics of the active sonar echo.Thus,it is of great significance in the field of theoretical research and sonar system performance analysis.