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本文考虑在一个移动的运载体上主动式声纳系统发射长连续波脉冲的情况下,降低混响的问题。在 WTI(动目标显示)雷达中,可认为杂乱回波在给定的多卜勒单元内是从一确定的方位上来的。与此情况有些不同的是,在主动式多卜勒处理声纳中混响在角度范围上是扩展了,主要因为散射体、波浪以及其他同类的东西都是在运动着。因此,抑制混响就需要接收机的指向性图具有更宽的零点。本文将从保持主瓣的约束条件下使波束形成器总的输出功率最小的观点出发,讨论基阵最佳化的基本问题。混响噪声场的协方差矩阵可以根据波浪运动所引起的扩展的经验结果以及接收换能器的几何特性来模造。由这些理想化的模型,计算并画出在各种不同的多卜勒频率单元、运载体速度与海况条件下最佳化的基阵响应图。其次,对实际换能器作了测量,在考虑到换能器本身的局限性的情况下,检验了自适应波束形成的实际性能。由于换能器响应图的不理想,影响了整体响应最佳化的程度,在这方面有一些结论。这些结论表明,有可能改进主动式换能器的设计。这对于在主动式声纳中充分发挥最佳与自适应技术的作用是很必要的。
This paper considers the issue of reducing the reverberation in the case of an active sonar system transmitting a long continuous wave pulse on a moving carrier. In WTI (Moving Target Display) radars, it can be assumed that the clutter echoes come from a definite orientation within a given Doppler unit. In a somewhat different situation, reverberation is extended over the angular range in active Doppler sonar processing, mainly because scatterers, waves, and other similar things are moving. Therefore, suppressing the reverb requires the receiver’s directivity map to have a wider zero point. In this paper, the basic problem of the optimization of the array is discussed from the viewpoint of keeping the total output power of the beamformer under the constraint of the main lobe. The covariance matrix of the reverberant noise field can be modeled based on the empirical experience of the expansion caused by wave motion and the geometry of the receiving transducer. From these idealized models, the matrix response maps are optimized and calculated for various Doppler frequency units, carrier velocities and sea state conditions. Secondly, the actual transducer was measured, and the actual performance of adaptive beamforming was tested considering the limitations of the transducer itself. Due to the poor response of the transducer, the overall response optimization has been affected. There are some conclusions in this respect. These conclusions show that it is possible to improve the design of active transducers. This is necessary to give full play to the best and adaptive technologies in active sonar.