机构地区: 中国科学院声学研究所
出 处: 《声学学报》 2009年第2期110-116,共7页
摘 要: 运动平台混响场的空频耦合结构对于改善主动声呐低速目标检测性能是十分关键的。本文通过对波束域混响采用高分辨谱分析方法(如MUSIC法和Capon法)在一定程度上突破了发射脉宽的制约,可以更为精确地给出低频混响场的方位-多普勒扩展估计。对南海实验数据的分析表明浅海低频混响场精确地符合运动多普勒规律,并且在一定距离方位分辨单元内的具有混响强度越高,频率扩展越小的特点。进一步的,利用运动多普勒关系给出偏航条件下左右舷混响在方位多普勒平面上沿不同曲线分布的规律,实验数据与理论预测符合良好。 The Space-Frequency coupling structure of platform-movement reverberation is important for suppressing LFAS (Low-Frequency high-power Active Sonar systems) reverberation and thereby improving its low-speed target detection performance. The high-resolution spectral analysis methods (e.g. MUSIC and Capon) are used to the beamformer-output reverberation sequences in order to overcome the restraint of the pulse width and hence obtain the LF (low-frequency) reverberation bearing-Doppler distribution more accurate. The South China sea-trial data analyses show that the shallow-water LF reverberation distribution exactly conforms to the Doppler effect and with the feature that its frequency-spread will decrease as the strength tends to increasing in the range-azimuth discrimination cells. Furthermore, the starboard-port reverberation separation characteristics of the platform yaw-moving conditions are deduced according to the Doppler effect and well matched by the experiment results of the same sea-trial.