光学学报, 2013, 33 (7): 0728003, 网络出版: 2013-07-01
大视场接收合成孔径激光成像雷达探测能力分析
Analysis on Detection Capability of Wide Field Receiving Synthetic Aperture Imaging Ladar
光电子学 光学外差接收 视场角 信噪比 阵列探测 optoelectronics optical heterodyne receiving field of view signal-to-noise ratio array detection
摘要
传统的合成孔径激光成像雷达外差接收天线结构,系统的视场角和有效孔径面积总是服从反相关关系,单方面提高其中一项并不能改善最终信噪比。从接收视场角、信号光可探测能力及系统的信噪比3个方面分析讨论了传统的望远镜接收、透镜接收及望远镜自差接收3种典型外差接收结构的优劣。结果表明,透镜单探测器接收结构能增大系统的接收视场,降低发射信号功率,但无法改善最终信噪比;透镜N阵列元的阵列探测器接收结构能保证较大接收视场和较强的探测能力,相对单探测器接收结构发射功率可降低为1/N,信噪比可提高N倍,比传统的望远镜及透镜接收结构有明显的视场大、口径大的探测优势。实验结果与Siegman光学外差接收天线理论吻合,研究结论也为其他光子极限外差探测系统相关参数的选定提供了参考。
Abstract
Field of view (FOV) and effective aperture area are always limited by a reciprocal relationship in conventional heterodyne receiving antenna system of synthetic aperture imaging ladar, leading that the final signal-to-noise ratio (SNR) can't be improved via unilateral increasing one. From key aspects of receiving viewing angle, detectable ability of signal light and SNR, relative merits of three typical heterodyne receiving structures are discussed, which are telescope for heterodyne receiving, focusing lens for heterodyne receiving, and telescope for self-heterodyne receiving. Qualitative analysis results, compared with telescope receiving structure, show that the heterodyne receiver using a lens and a detector can expand the system′s receiving viewing angle and reduce the emission signal power, but can′t enhance the SNR actually, while the heterodyne receiver using a lens and an array detector with larger FOV and stronger detection ability has a reduction to 1/N in transmitting power and N times improvment in final SNR.The conculusions of this study meet with Siegman′s optical heterodyne receiving antenna theory and provide a certain reference to the parameter choosing of other heterodyne detection systems working in the photo-limited regime.
卢栋, 孙建锋, 周煜, 职亚楠, 马小平, 刘立人. 大视场接收合成孔径激光成像雷达探测能力分析[J]. 光学学报, 2013, 33(7): 0728003. Lu Dong, Sun Jianfeng, Zhou Yu, Zhi Ya′nan, Ma Xiaoping, Liu Liren. Analysis on Detection Capability of Wide Field Receiving Synthetic Aperture Imaging Ladar[J]. Acta Optica Sinica, 2013, 33(7): 0728003.