基于相关法方位分析的水下主动目标尺度识别研究

On Underwater Target Dimension Recognition Based on Bearings Analysis of Signal Correlation Feature

水下目标识别技术是现代声纳系统与水声对抗的一个极为重要的组成部分。它是随着声纳技术、信号检测理论、计算机技术等的进步而发展起来的 ,目前有多种识别方法。由于水下目标回波亮点结构是重要的目标特征 ,因此对目标回波亮点时空特征的提取已成为水下主动目标识别的一种有效方法。文中研究了水下高频 ( 2 0～ 35 k Hz)主动声学目标的识别方法及仿真性能。首先基于水下潜艇目标回波的亮点空间方位特征 ,提出了水下目标回波多亮点方位估计算法。然后 ,研究了目标亮点视在方位的模糊特性 ,给出了舷角与空间视在目标张角的关系。最后 ,进行了仿真实验 ,结果表明 :相关法方位分析的水下主动目标识别算法抗噪声能力强 ,在 S/N =0 d B时仍能很好地完成目标识别功能 ;在近正横附近 ,在距离 5 0 0 m处仍可完成目标尺度识别功能 ;在舷角 70°～ 2 0°扇面有良好的尺度识别能力 ;采用复杂波形 ,复本相关处理后可得到目标亮点时域信息和亮点方位信息。

Underwater target identification technology is a very important part of modern sonar system and underwater acoustic antagonizing. At present, there are only few target identification methods based on extracting active target echo features. This paper mainly makes a research on underwater high frequency(20～35kHz) active echo recognition method and its performance. The range of frequency is appropriate to detect small aperture acoustic transducer array and medium distance acoustic field. First, on the basis of the space bearings feature of underwater submarine target echo highlight, the bearings recognition algorithm of underwater target multiple highlight echo is presented (see Formula (6)). This method makes space identification in frequency domain, whereas traditional methods are in time domain. Then, the illegibility property of target highlight on the instantaneous bearings is researched and the relationship between broad side angle and space target extension angle (see Formula (13)) is presented. Finally, simulation experiment is carried out. Simulation results (see Tables 4 and 5) show that the algorithm has a strong anti noise ability which can correctly recognize target even at S/N =0 dB and at 70°～20° attacking angle. When adopting complicated waveform, we can get time domain information and bearings information of target highlight with processing of copy correlation. This method is easy and practical, and it is very stable