Author Affiliations
Abstract
1 Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
A 1550 nm all-fiber pulsed laser Doppler vibrometer (LDV) based on time-domain chopping techniques is developed to overcome demodulation failures caused by multipath interference. The system adopts an adjustable configuration on pulse duration and pulse repetition frequency according to the distance. An experiment is carried out at a 25 m standoff with pulse duration of 80 ns, single pulse energy of 0.4 nJ, and pulse repetition frequency of 1 MHz. A waveform and spectrogram of the demodulated voice show that the pulsed LDV system has a good performance in long-range voice listening.
120.7280 Vibration analysis 280.3340 Laser Doppler velocimetry 040.2840 Heterodyne Chinese Optics Letters
2019, 17(5): 051201
1 中国科学院长春光学精密机械与物理研究所激光与物质相互作用国家重点实验室, 吉林 长春 130033
2 中国科学院大学, 北京 100049
以远程脉冲激光外差探测系统为模型,推导了系统的信号与噪声的表达式,给出了脉冲激光外差探测系统匹配滤波算法流程,对匹配滤波技术在中程导弹与国际空间站目标探测中的详细应用过程进行了仿真,分析了目标距离、散射截面面积、数字采样率对探测能力的影响。仿真结果表明:在100 MHz采样率的数字处理能力下,分别用蒙特卡罗法仿真了500次匹配滤波过程,对于散射截面面积为5 m
2、距离为100 km的中程导弹,回波信号载噪比为3.29 dB,匹配滤波后信号载噪比为25.13 dB,信号强度增强了152倍,距离精度为27 m,速度精度为0.17 m/s;对于散射截面面积为100 m
2、距离为500 km的国际空间站,回波信号载噪比为-6.12 dB,匹配滤波后信号载噪比为18.49 dB,信号强度增强了289倍,距离精度为117 m,速度精度为2.1 m/s。目标距离越小,散射截面面积越大,数字采样率越高,匹配滤波提取增强信号的能力越强。
遥感 脉冲激光 外差探测 匹配滤波 蒙特卡罗 载噪比
