随机起伏海面运动目标声散射联合建模与统计特性研究

For acoustic wave scattered by the moving targets on randomly undulatory sea surface is time varying, underwater acoustic guide equipments are facing great challenges in locating and identifying the surface targets. Therefore, it is a key problem to jointly model acoustic scattering of the moving targets on randomly undulatory sea surface efficiently and accurately as well as the corresponding statistical rule. On the requirement of acoustic active detection on the surface targets, the main contents are arranged as follows: joint modeling and fast calculation method on wave scattered by the moving targets on randomly undulatory sea surface will be proposed. The influence of random varying sea surface and moving targets on the scattering characteristics and mechanism of scattering coupling between sea surface andsurface targets will be studied. Non-Gauss statistical model will be established to express the complex time-varying characteristics of scattering from moving targets on randomly undulatory sea surface and the statistical role will be studied. Experiments on acoustic scattering characteristics of moving targets on randomly undulatory sea surface will be made to verify the accuracy of model, main factor and corresponding roles. The research results will provide a theoretical basis and an evaluation method for acoustic active recognition or stealth design on surface ships, submerged vessels and floating building.

由于随机起伏海面运动目标回波是时变的，水下主动声制导设备对水面目标的定位与识别面临着巨大的挑战。为此，寻求精确、高效的随机起伏海面大尺度运动目标声散射联合建模与快速计算方法，掌握其回波精细特征以及统计规律是亟待解决的关键问题。立足于海面运动目标主动声探测的关键问题，本项目开展的研究工作主要如下：建立随机起伏海面运动目标声散射联合模型与快速计算方法；研究海面起伏、目标姿态对目标回波的影响规律；掌握随机起伏海面运动目标与海面耦合散射机理；分析随机起伏海面运动目标声散射时、空、频精细特征；建立表征随机起伏海面运动目标声散射复杂时变性的非高斯物理统计模型；分析随机起伏海面运动目标声散射统计特性；开展起伏海面运动目标声散射特性实验，验证预报模型、精细特征、统计特性以及影响规律的准确性。为水面舰船、半潜舰艇、水面建筑的主动声识别、声隐身提供必要的理论基础与参考依据。

由于随机起伏海面运动目标回波是时变的，水面目标的定位与识别面临着巨大的挑战。寻求精确、高效的随机起伏海面和目标声散射联合建模与快速计算方法，掌握其回波精细特征以及统计规律是亟待解决的关键问题。项目已经开展的主要研究内容包括：基于Simulink和V-Realm Builder 虚拟现实技术创建船舶运动模型，在风浪流联合作用下构建船舶六自由度运动简化的数学建模，在VR视景浏览器中模拟船舶运动能够很好地体现船舶的运动视景，为提高水面运动目标声学探测能力和识别精度提供基础。建立二维声场条件下起伏海面目标声散射数值计算的简化模型，获得海面起伏参数的变化规律，并对其散射总能量的统计特性进行解释，对于识别动态水面舰船有一定的参考作用。深入开展起伏海面条件下水面舰船声散射特性研究，分析随机起伏海面运动目标姿态、海面起伏变化对其声散射特性的影响规律。重点解决起伏波浪谱条件下声散射特性统计规律分析方法，掌握运动目标与起伏海面之间耦合散射机理。提出两种海面舰船目标多径声散射模型，利用简谐运动合成法建立了海面舰船目标多径声散射简化模型，将海面对水面船的六个自由度幅度和周期的影响考虑为经验统计值。利用海面舰船目标多径声散射简化模型，分析了在不同探测角上六个自由度对声散射的贡献度。基于切片理论建立了随机起伏海面舰船目标六自由度动力学模型，在此基础上，根据起伏海面的反射系数统计数据，运用蒙特卡洛法建立了起伏海面作用下海面船的多径声散射模型。开展水面舰船缩比模型声散射实验，获取运动水面舰船声散射特性，从船模声散射实测结果和计算结果中，均发现波浪作用下船舶的回声强度随时间符合χ2分布的统计规律。探索和发现起伏海面运动目标新的时、空、频精细特征以及统计特性，为水面舰船声散射预报模型验模提供基础。