【作者】 顾怡鸣； 宫在晓； 李整林；

【Author】 GU Yiming;GONG Zaixiao;LI Zhenglin;Institute of Acoustics, Chinese Academy of Sciences;

【机构】 中国科学院声学研究所；

【摘要】 目标深度是目标分类的重要信息,主动声呐可以获取目标的距离信息,但无法直接估计目标深度。针对该问题提出了一种利用散射声场干涉图案的浅海负跃层环境中目标深度判别方法,该方法利用目标回波在水平阵上形成的干涉特征对目标深度进行分类。浅海负跃层声速剖面条件下,存在海面海底反射和负跃层折射两种不同类型简正波。目标位于不同深度时,在海底水平阵上会形成不同形式的干涉图案。计算了跃层上方和下方目标散射声场的干涉图案,并提取了对应的波导不变量谱。仿真结果表明,目标在负跃层以上时,声场由折射类简正波占主导,波导不变量谱的峰值位于1附近;目标在负跃层下方时,反射类简正波占声场的主要成分,波导不变量谱会出现大于1的峰值,利用波导不变量的分布情况可以判断目标在跃层的上方或下方。更多还原

【Abstract】 The target depth is critical information for target classification. Active sonar can obtain the distance information of the target, but it cannot directly estimate the target depth. A method based on the interference pattern of the scattered sound field is proposed to discriminating the target depth in shallow water with negative thermocline.This method uses the interference feature generated by target echoes on the horizontal array to classify the target depth. There are two different types of normal mode in negative thermocline environment, which are reflected on the sea bottom and refracted by the thermocline. When the target is located at different depths, different forms of interference patterns will be formed on the seabed horizontal array. The interference patterns of the sound field scattered by the target above and below the thermocline are calculated, and the corresponding waveguide invariant spectrums are extracted. The simulation results show that when the target is above the negative thermocline, the scattered sound field is dominated by refraction normal modes, and the peak of the waveguide invariant spectrum is located near 1. When the target depth is below the negative thermocline, the reflected normal mode account for the main component of the sound field, and the waveguide invariant spectrum will have peaks greater than 1. The distribution of the waveguide invariant can be used to determine whether the target is above or below the negative thermocline.更多还原