【作者】 陈洁；

【导师】 方尔正；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2009， 硕士

【摘要】 激光作为一种具有高亮度、高准直度的光源,被广泛地应用在各种领域,而激光测量手段与声纳技术相结合的方法作为一种新兴的探测技术,近年来也受到了普遍关注。本文阐述了目前水下目标激光声纳探测的基本原理和发展概况。文中推导了水面微波的一维理论模型,研究了在水—空气交界面处的声信号反射与折射问题,给出了水表面质点振速、位移与水下目标辐射声信号之间的关系。在此基础上,本文阐述了激光直接强度调制法探测水下目标的基本原理,给出了目前激光声纳探测系统的大致探测能力。通过仿真获得了不同声源级与频率的水下信号在激光声纳探测中的表现。依据上述原理,作者设计了基于激光直接强度调制法的激光声纳探测系统,包含光学、机械和电路等三个主要部分。系统采取调制光源作为探测信号,采用光敏二极管面阵作为接收组件,大大提高了系统的灵敏度和抗干扰能力。文中还给出了采用ARM嵌入式处理器结合嵌入式实时操作系统构建的激光探测信号采集系统。最后,作者利用所设计的激光声纳探测系统进行了在空气中实验和消声水池实验,得到了平静水面和有剧烈干扰条件下的测试数据。数据处理结果表明,利用激光直接强度调制法探测水表面微波是可行性的,所设计的激光声纳探测系统具有一定的实用性。更多还原

【Abstract】 As a kind of illuminant with high brightness and high collimation, laser is widely used in various fields. A new detection technology, combined with Laser detection and sonar technology, has received universal attention.Principles and development situation of laser-based sonar detection are described. One-dimensional model for the surface perturbation is derived, the reflection and refraction of sonar signal on water-air interface are studied, and the relationship between particle vibration velocity, displacement on water interface and underwater target radiated signal is given. On this basis, the principles of underwater target detection using direct laser intensity modulation method are described, the approximate detection ability of present laser-based sonar detection system is given. The manifestations of underwater signals with different source levels and frequencies in laser-based sonar detection are acquired by simulation.According to the principles mentioned above, a laser-based sonar detection system using direct laser intensity modulation method is designed, which includes optics, machinery and circuit these three main aspects. Modulated light is used as detecting signal in this system, photodiode area array is used as receiving module, which greatly improves the sensitivity and anti-interference ability of the system. A signal acquisition system for laser-based sonar detection system is constructed based on ARM embedded processor and real-time operating system.Experiments in the air and in an anechoic tank are both carried out lastly, the experimental data in calm water surface condition and violently disturbed water surface condition are acquired. The processing results prove the feasibility of surface perturbation detection based on direct laser intensity modulation method and the applicability of the laser-based sonar detection system designed.更多还原