相干激光主动成像与跟踪技术研究

发布时间：2019-06-21 02:42

【摘要】：随着空间态势的不断变化,对远距离空间目标的成像探测和识别能力的需求不断增长。相干激光主动成像技术突破传统成像概念,采用激光主动照明并探测反射回波频谱信息的方式,使成像分辨率不再受限于接收器口径,能极大地提高成像分辨率。在对多种空间运动目标高分辨率成像时,有时要求达到亚角秒级的高跟踪精度。然而,由于大气湍流降低了远程运动目标跟踪系统的性能,使得湍流环境下对空间运动目标的精密跟踪问题成为相干激光主动成像技术亟待解决的关键问题。本文在研究相干激光主动成像技术的基础上,推导了三光束成像系统接收端探测到的能量公式,仿真并分析了目标频谱信息量与频谱分布、孔径位置误差、主动跟踪误差对相干激光主动成像质量的影响。以达到满足成像质量要求的主动跟踪精度为目的,给出了地基激光主动跟踪系统总体设计思路,详细地叙述了其APT(捕获、指向、跟踪)系统的工作原理,并分离出精跟踪单元作为关键技术研究。阐述了激光主动跟踪的相关大气理论和解决方案,设计并搭建了激光主动精跟踪的室内实验平台,模拟出符合大气湍流功率谱特性的波前整体倾斜信号,再运用自适应光学技术进行探测和校正。实验结果证明:将高速倾斜镜运用到精跟踪中,可以有效抑制湍流、提高跟踪精度。最后,对实际系统中的主动跟踪误差进行了分析。
[Abstract]:With the continuous change of space situation, the demand for imaging detection and recognition ability of long-distance space targets is increasing. Coherent laser active imaging technology breaks through the traditional imaging concept and adopts laser active lighting and detection of reflected echo spectrum information so that the imaging resolution is no longer limited to the receiver aperture and can greatly improve the imaging resolution. In the high resolution imaging of a variety of spatial moving targets, it is sometimes required to achieve the subangular second level of high tracking accuracy. However, because atmospheric turbulence reduces the performance of remote moving target tracking system, the problem of precise tracking of spatial moving targets in turbulent environment has become a key problem to be solved urgently in coherent laser active imaging technology. In this paper, based on the study of coherent laser active imaging technology, the energy formula detected by the receiver of three-beam imaging system is derived, and the effects of target spectrum information and spectrum distribution, aperture position error and active tracking error on the quality of coherent laser active imaging are simulated and analyzed. In order to meet the requirements of imaging quality, the overall design idea of ground-based laser active tracking system is given, the working principle of its APT (capture, pointing, tracking) system is described in detail, and the fine tracking unit is separated as the key technology. The related atmospheric theory and solution of laser active tracking are described, and the indoor experimental platform of laser active fine tracking is designed and built. The wavefront integral tilt signal which accords with the characteristics of atmospheric turbulent power spectrum is simulated, and then the adaptive optical technology is used to detect and correct it. The experimental results show that the application of high speed tilt mirror to fine tracking can effectively suppress turbulence and improve tracking accuracy. Finally, the active tracking error in the actual system is analyzed.
【学位授予单位】：中国科学院研究生院(西安光学精密机械研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.41;TN249

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