1 中国科学院上海光学精密机械研究所 空间激光信息传输与探测技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
提出了一种直视合成孔径激光雷达的高速空间相位调制方法。将一束空间偏振光束分为两束同轴同心且正交偏振的光束。在交轨向, 将两个光束调制成随时间正弦变化且变化方向相反的空间相位; 在顺轨向, 将两束光调制成具有符号相反曲率半径的相位, 在慢时间轴上产生与目标顺轨向位置有关的空间二次项相位历程。此种调制方法, 在顺轨向具有自动补偿抖动的功能, 可以有效地防止平台抖动对成像的影响。
合成孔径激光雷达 直视 高速 相位调制 synthetic aperture ladar down-looking high-speed phase modulation 红外与激光工程
2018, 47(10): 1030001
1 中国科学院上海光学精密机械研究所中国科学院空间激光信息传输与探测技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
本振增强直视合成孔径激光成像雷达(SAIL)发射两束同轴且偏振正交的光束,采用外差接收方式接收回波信号,在数据处理过程中对两束偏振正交回波光束携带的目标信号自差,以达到消除大气扰动、运动平台振动和雷达系统本身产生的相位扰动的目的。对该雷达系统的二维成像实验装置进行了描述,并给出了该雷达系统对二维目标成像的信号获取过程和数据处理过程。实验实现了3.6 mm×3.6 mm的分辨率,并对两个二维点阵目标进行成像,取得了良好的成像对比度,证明了该雷达对二维目标成像的可行性。
遥感 传感器 激光雷达 合成孔径雷达 相干探测 匹配滤波 激光与光电子学进展
2018, 55(6): 062802
1 中国科学院上海光学精密机械研究所空间激光信息传输与探测技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
进行了1.8 km和3.4 km的直视逆合成孔径激光成像雷达外场实验,给出了远距离成像模式下考虑相位延时的非线性校正算法。实验中,目标为放置在无人机上的角锥和包裹有反射纸的无人机。通过交轨向包络对齐和顺轨向相位补偿算法,先后得到了不同成像距离下的角锥目标图像和1.8 km成像距离下的无人机图像。成像距离为1.8 km时二维分辨率达到了7.2 mm×5.8 mm,成像距离为3.4 km时二维分辨率达到了12.7 mm×9.2 mm。
大气光学 直视逆合成孔径 激光成像雷达 空间相位调制 外场实验
1 中国科学院上海光学精密机械研究所空间激光通信与探测技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
本文开展了多通道宽幅度合成孔径激光成像雷达(SAIL)收发装置的优化研究,提出了一种实现远场瞬时宽幅式的成像方法,并给出了多通道宽幅度SAIL收发装置的结构图。重点对发射光路进行了研究,分析了光纤阵列器中发射光束排布的特点,并给出了光纤阵列器中发射光纤的倾斜排布方案。而后,对发射光纤排布方案进行了优化,建立了多通道宽幅度SAIL发射装置的发射光束排布模型,给出了光纤阵列器中发射光束排布的最佳方案并进行了分析。最后,给出了多通道宽幅度SAIL接收装置中阵列探测器的结构图。这对远距离高分辨率宽幅度的机载SAIL研究具有重要的意义。
遥感 激光雷达 光纤排布 优化模型 多通道
Author Affiliations
Abstract
1 Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
A specific system structure of down-looking synthetic aperture imaging ladar (SAIL) is given, and a far-field experiment over 6 km of down-looking SAIL under this system design is carried out. The down-looking SAIL can overcome the influence of atmospheric turbulence to a great extent. By applying this system design, it also has advantages in self-compensating phase modulation. A fine image is obtained after aligning in the orthogonal direction and phase error compensation in the travel direction based on a dominant scatterer. The achieved imaging resolutions in the two dimensions are both better than 5 cm.
280.6730 Synthetic aperture radar 280.3640 Lidar 100.2000 Digital image processing 100.3010 Image reconstruction techniques Chinese Optics Letters
2017, 15(8): 082801
Author Affiliations
Abstract
1 Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
This Letter gives the general construction of an enhanced self-heterodyne synthetic aperture imaging ladar (SAIL) system, and proposes the principle of image processing. A point target is reconstructed in the enhanced self-heterodyne SAIL as well as in down-looking SAIL experiments, and the achieved imaging resolution of the enhanced self-heterodyne SAIL is analyzed. The signal-to-noise ratio (SNR) of the point target final image in the enhanced self-heterodyne SAIL is higher than that in the down-looking SAIL. The enhanced self-heterodyne SAIL can improve the SNR of the target image in far-distance imaging, with practicality.
280.3640 Lidar 280.6730 Synthetic aperture radar 100.2000 Digital image processing 100.3010 Image reconstruction techniques Chinese Optics Letters
2017, 15(10): 102801
中国科学院上海光学精密机械研究所空间激光信息传输与探测技术重点实验室, 上海 201800
报道了一个正弦相位调制的大视场机载直视合成孔径激光成像雷达。在室外3.8 km进行了视场扫描并获得了高分辨率合成孔径成像。同时给出了该机载直视合成孔径激光成像雷达的3 km飞行试验结果, 获得了高质量大视场图像, 其成像视场提高了一个量级, 达到了4.8 mrad。
遥感 激光雷达 机载直视合成孔径激光成像雷达 大视场 正弦相位调制
1 中国科学院上海光学精密机械研究所空间激光信息传输与探测技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
用15 m的平行光管模拟远场条件对直视合成孔径激光成像雷达(SAIL)的滑动聚束模式进行了研究。基于单点目标回波收集方程,分析了滑动聚束的信噪比特性,理论和实验证实滑动聚束模式可以通过延长有效采集时间长度的方式提高信噪比。
成像系统 合成孔径激光成像雷达 滑动聚束模式 信噪比
Author Affiliations
Abstract
Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
We present a tabletop-scale spotlight-mode down-looking synthetic aperture imaging ladar (DL SAIL) demonstrator, which is performed by a collimator with 10 m focal length to simulate the far-field optical field. A specular-point target and a diffuse-reflection target have been used for resolution analysis and 2D imaging, respectively. The experimental result is in agreement with the theoretical design. The experiment setup is capable of simulating a real application scenario for further study. This Letter is focused on the proposition and implementation of spotlight-mode DL SAIL.
100.2000 Digital image processing 100.3010 Image reconstruction techniques 110.0115 Imaging through turbulent media 280.6730 Synthetic aperture radar Chinese Optics Letters
2015, 13(9): 091001