水下目标的激光声探测技术

摘要

The possibility of the laser induced sound as the sound source of high resolution image sonar in theory is discussed. The laser induced sound producing and measuring system is set up: the transmitted beamwidth and the directivity index of laser induced sound transducer are derived. The range resolution and the maximum detection ranges of laser induced sound in backgrounds of noise and reverberation are calculated. The results show that the range resolution and the maximum detection ranges of the laser induced sound are high enough to detect the target. The laser induced sound can be the sound source of image sonar in theory.%高能脉冲激光聚焦于液体中,光击穿会伴随着光、声和空泡脉动等现象,其中击穿时等离子体膨胀产生的声和随后的空泡脉动产生的声统称为激光声.对产生的激光声信号进行分析,论证激光声信号应用于水下探测的可行性.设计激光声产生和测量分析系统,计算激光声信号的波束指向性、距离分辨力、噪声背景下和混响背景下的探测距离.结果表明,激光声声源在距离分辨力和声源级两方面满足对水下目标探测的要求.从理论推导和计算上初步证明了激光声信号可以应用于水下探测领域.