基于谐波集检测的飞行目标水下声探测算法研究

Research on Underwater Acoustic Detection Algorithm of Aerial Targets Based on Harmonic Set Detection

螺旋桨飞机以一定高度在水面上飞行时,其噪声谱中的线谱存在明显的谐波关系。随着噪声由空气入水的跨界传播以及水下传播环境的变化,谐波关系有减弱的趋势。针对此问题,提出了基于谐波集检测与最强谱线检测相结合的检测算法。该算法采用门限调节因子来自适应地调整检测门限,提高了远距离低信噪比情况下目标的探测性能,可以有效地在水下环境检测螺旋桨飞机。水下单水听器接收的实测信号检测结果表明,对于巡航速度为36m/s的螺旋桨飞机,探测距离可以达到2.48km.

The line spectrum in noise spectrum has obvious harmonic relation when a propeller-driven aircraft flies over the water surface at a certain height. With the cross-border propagation of noise from air to water and the change of underwater propagation environment, the harmonic relation tends to weaken. To solve this problem, an underwater acoustic detection algorithm based on the combination of harmonic set detection and strongest line detection is proposed, and the detection threshold is adaptively adjusted by using the threshold adjustment factor α, which improves the target detection performance under the condition of the low signal-to-noise ratio at a long distance and can effectively detect the propeller-driven aircrafts in underwater environment. The detection results of the measured signals received by the single hydrophone in water show that the detection distance can reach 2.48 km for a propeller-driven aircraft with a cruise speed of 36 m/s.