基于多片高性能DSP的主动声呐低速运动小目标探测系统

Multi-chip DSP System for Active Sonar Detecting Low-speed Small Targets

自主水下航行器(AUV)等水下运动平台的主动声呐在浅海复杂环境工作时,其性能容易被杂波造成的虚警影响,难以完成对低速小目标的探测。针对这一问题,探测系统采用了具备杂波抑制能力的二进制相移键控(binary phase shift keying,BPSK)波进行目标探测。但BPSK波多普勒敏感、速度容限小、易失配,需要大量的副本覆盖检测范围,处理过程计算量大。为了解决这一问题,文中采用6片高性能数字信号处理器(DSP)芯片构成的信号处理机,设计了与硬件平台适应的处理算法,并对软件进行了实时性优化。经过实时性测试,该系统可在160 ms内完成发射脉宽200 ms的BPSK波1帧回波数据的实时处理。湖试试验中,该系统可检出预先布置在1360 m处,航速1 kn,目标强度3 dB的应答器。试验结果表明,该探测系统可在复杂水下环境实时有效探测低速小目标。

The active sonar equipped on underwater moving platform such as autonomous undersea vehicle(AUV)is easily affected by clutter when it works in shallow water,which makes it hard to detect low-speed small targets.In this paper,the detecting system uses binary phase-shift keying(BPSK)waveform to reduce the clutter.To conquer the high computing burden of BPSK waveform,a signal processor composed of 6 high performance digital signal processor(DSP)chips is used in this paper,and a processing algorithm suitable for the hardware platform is designed,and the software is optimized in real time.Real-time test result shows that the system can complete the processing of one frame of echo data within 160 ms when the pulse width is 200 ms.Lake test verifies that the system can detect the transponder which is pre-arranged at 1360 m,with a speed of 1 kn and a target strength of 3 dB.Test results show that the detecting system can effectively detect low-speed small targets in complex underwater environment in real time.