摘要
使用低频大基阵如拖线阵、舷侧阵等是近代声呐发展的主要倾向之一。通常这类基阵工作在边界层压力起伏及指向性噪声干扰分量占优势的背景噪声中，为抑制这类噪声，本文基于背景噪声的不同物理特性，打破传统的半波长间距布阵理论的限制，提出密集间距大基阵分段折线模型及分步波束形成方法，并对阵形畸变的影响及减少畸变损耗的途径进行了分析和计算机模拟。结果表明，和相同条件下常规布阵方式相比，不但ＳＮＲ增益可提高一个数量级左右，而且自噪声级将大为下降，数字处理设备大为简化，对基元位置不定性的灵敏度也有所降低，大幅度地提高被动检测系统的品质因素。
It is one of the main trends in mordern sonar development to use a low frequency line array of large aperture, e.g. a towed line array and a flank array, etc. These arrays generally operate in a background noise where the turbulent flow fluctuations and the directional noise from self--ship are the dominant noise components. In order to eliminate the influence of the noise disturbances on their performance,the segmentation broken line model of a densely spaced large array and the fractional beamforming technique are presented in this paper, which are based on the physical properties of the background noise and have been a break through on the treditional concept of an array with half--wavelength spacing between elements.The influence of array shape distortion and the reduction method of its distortion lOsses for the array model have also been analysed and simulated by a computer. The result shows that not only the SNR gain of the array is raised by about ] 0 dB, but also the self--noise level is considerably decreased. It also shows that the complexity of signal precessors is obviously simplified and the sensitivity of element location uncertainty to the array performance is reduced. As a result, the Performance Figure of the passive detection system is greatly increased.
出处
《声学学报》
EI
CSCD
北大核心
1996年第4期661-671,共11页
Acta Acustica
