Study of digital quadrature techniques applied in active laser surveillance
-
摘要: 提出基于光学系统的“猫眼”效应,应用单频调制的连续激光,对扫描式红外热成像目标进行有效探测的新方法。分析了光学系统的后向反射特性,针对回波信号特征,提出利用回波信号的相位信息,采用直接采样的数字正交检波技术实现对低信噪比回波信号的可靠检测,并在外场试验中应用该方案对实际目标回波信号获得了满意的检测结果。Abstract: Based on the optical systems' "cat' s eye" effect,a new technique working with single frequency modulated CW laser against IR scanning imaging systems is provided.The retrodirective reflection of the optical systems against the incident laser is discussed and based on the analysis of echo signals' characteristics.A digital quadrature coherent detector is used to detect such signals with low S/N ratio and the expected results is obtained in experiments.
-
-
[1] MEI S Sh.Optoelectronic technology-a star in the information equipments[M].Beijing:National Defence Industry Press,1999.1～21 (in Chinese).
[2] MA H Zh.Study on the reflective characteristics of the targets and the "cat's eye" effect[J].Laser Technology,2003,27(6):600～602(in Chinese).
[3] ZHAO X J,GAO Zh Y,ZHANG Y Y.Technique of active laser reconnaissance and the applications in the military[J].Optical Technique,2003,29(4):414～416(in Chinese).
[4] ZHAO Sh J.Theory of signal detection and estimation[M].Xi'an:Xidian University Press,1998.15～70(in Chinese).
[5] CHEN C K.New approaches for the design of minimal quadrature mirror filters with continuous and powers-of-two coefficients[J].Signal Processing,1997,56(2):269～278.
[6] SINSKY A I,WANG P C P.Erroe analysis of a quadrature coherent detector processor[J].IEEE Trans Aerospace Electron Syst,1974,AES-10(5):880～883.
[7] ZHENG X F,ZENG T,ZHU Sh Y.Intermediate frequency sampling based on the hilbert transform and its hardware implementation[J].Journal of Beijing Institute of Technology,2004,24 (1):57～60(in Chinese).
[8] RICE D W,W U K H.Quadrature sampling with high dynamic range[J].IEEE Trans Aerospace Electron Syst,1982,AES-18(4):736～739.
计量
- 文章访问数: 0
- HTML全文浏览量: 0
- PDF下载量: 5
下载: