水下水平阵对空中运动声源的线谱探测

由于空气、海水介质声阻抗差异巨大,空中声源辐射的噪声透射入水的能量损失很大,加之水中声源目标的干扰,从水下探测空中声源相对困难。海试数据分析表明,空中高速运动声源噪声透射入水后信号较弱,在频繁存在干扰的水下声场环境中,常规宽带波束形成方法难以生效.针对空中声源普遍存在线谱的特点,首先利用线谱识别、提取与跟踪以及线谱加密技术对水下水平阵接收信号进行线谱分析,再通过剔除强干扰目标的线谱,成功分离出包含空中声源的线谱信号,实现对空中运动声源的探测,最远距离达16.8 km。通过理论和实验数据分析,验证了探测结果的正确性. 

Line spectrum detection of airborne moving source by underwater horizontal array

Owning to the great difference of the acoustic characteristic impedances between the air and the sea water,energy of the sound propagating in water due to an airborne source suffers significant transmission loss.In addition,the existence of the interferences induced by the underwater sound sources makes it even more difficult to detect the air target from the water.An experiment for helicopter detection using underwater horizontal array was carried out in the northern South China Sea in January 2018.The data analysis shows that the helicopter noise is weak when it transmits into water,so it is difficult to detect helicopter effectively by using the conventional broadband beamforming method especially with frequent underwater interference.In view of the line spectrum characteristics of airborne source,line spectrum recognition,extraction,tracking and line spectrum encryption technology are used to analyze the received signal.Then,by eliminating the line spectrum of strong interference,the airborne source is successfully detected,and the longest distance is 16.8 km.The accuracy of the detection results is verified by experiment and theoretical analysis.