光学学报, 2015, 35 (2): 0212006, 网络出版: 2015-01-09
声光移频器对微多普勒效应探测的影响研究
Research on Infulence of Acousto-Optic Frequency Shifter to Micro-Doppler Effect Detection
测量 微多普勒效应 声光移频器 相干探测 measurement micro-Doppler effect acousto-optic frequency shifters coherent detection
摘要
为实现基于微多普勒效应的远距离目标探测和识别,研究了采用声光移频器的激光外差相干探测结构对目标微多普勒特征探测的影响。建立了声光移频器驱动功率与系统信噪比之间的数学模型,并进行了仿真计算,搭建了1550 nm 激光外差/零差相干探测实验平台对所建模型进行了验证。研究结果表明:在移频器驱动电压限定范围内,驱动电压越高,对微多普勒效应探测的效果越好,得到的目标特征越明显,与理论分析一致。通过对比实验发现在同样条件下,外差探测得到的反映目标特征的时频分布曲线较零差的清晰,特征提取误差小,可读性更高,说明外差探测结构更有利于复杂的远距离目标探测。
Abstract
In order to detect and recognize remote targets based on micro-Doppler effect,the influence of heterodyne lidar system composed by acousto-optic frequency shifters to micro-Doppler feature extraction is researched. Mathematical models between driving power of frequency shifter and signal to noise ratio are established, and simulations and experiments are performed through 1550 nm experimental system to verify their validity. The research shows that within the limiting driving voltage scope, the higher the voltage, the better the detection result is, which is in accordance with the theoretical analysis. Through the contrast experiment,heterodyne detection system is found better than homodyne in time-frequency curve of target feature acquisition. The smaller extracting error and the higher readability indicate that heterodyne system is more conductive than complicated remote target detection.
郭力仁, 胡以华, 李政, 徐世龙. 声光移频器对微多普勒效应探测的影响研究[J]. 光学学报, 2015, 35(2): 0212006. Guo Liren, Hu Yihua, Li Zheng, Xu Shilong. Research on Infulence of Acousto-Optic Frequency Shifter to Micro-Doppler Effect Detection[J]. Acta Optica Sinica, 2015, 35(2): 0212006.