低频大孔径线列阵声呐在海底反射区的测向性能分析

Deep water azimuth predication using bottom bounce sound received by a low frequency large aperture linear array

与深海直达声探测、会聚区探测不同,在海底反射声探测模式下,低频大孔径线列阵声呐采用常规阵列信号处理方法,会产生测向误差增大和方位分裂等测向性能下降现象。目前,关于海底反射声探测模式下测向性能下降程度的预报、测向性能下降现象出现的区域位置预报等方面尚缺乏研究。该文针对该问题,提出一套海底反射区声呐测向性能预报方法。该方法以深海声场存在简正波簇现象及高阶简正波簇在角谱域分布具有稳定性等分析结论为支撑,提出高阶简正波簇角谱域分布向空域分布的转换方法、高阶简正波簇引起的测向误差量值预报方法、不同高阶简正波簇干涉产生多目标现象的条件的计算方法,实现了对低频大孔径线列阵声呐在深海海底反射区不同位置的测向误差预报、目标方位分裂现象产生的位置和目标角度范围要求预报。

Different from direct sound detection and convergence zone detection, there are limitations while conventional array signal processing applying in bottom bounce sound areas, including phenomenon as direction error increasing and azimuthal splitting. So far, the areas where the phenomenon exists and the predication of decline degree are to be studied. Aiming at issues above, the paper develops a method for deep water azimuth predication. First, the paper submits concepts of normal mode cluster and verifies the stability of high normal mode cluster in angular spectrum. Based on these, the paper develops the method deriving the spatial distribution of normal mode cluster using the position in angular spectrum, and the method predicating the direction error arousing by each high normal mode cluster, and the method for calculating azimuthal splitting conditions caused by the interference of two normal mode clusters. Above all, the method realizes the predication of the areas where the phenomenon exists and the decline degree.