摘要
合成孔径成像激光雷达是一种新的主动式有源成像系统,它的一个突出优势是可以获得比合成孔径雷达更高的分辨率,和更接近光学图片的效果。首先,概述了理想情况下旋转目标成像的基本原理,分析了合成孔径成像激光雷达的二维分辨率。然后,针对合成孔径成像激光雷达实验中遇到的实际问题,即不能实现理想转台,会引入平动使包络相位无法对齐,进而影响成像质量,甚至无法成像,给出包络对齐和初相校正的平动补偿方法。包络对齐利用脉冲之间的相关性进行对齐;初相校正以转台模型的理想转台中心的相位为基准实现相位的对齐。最后,给出实验系统框图、工作模式、实验参数设计和最终成像效果图,对比了包络对齐和初相校正的结果,验证了系统的有效性和平动补偿的必要性。
Synthetic aperture imaging lidar is a new active imaging system, which can offer a better azimuth resolution than that in conventional SAR system, and obtain the imaging effect close to optical picture. Firstly, the basic principle of rotating objects imaging under ideal condition was introduced , and the 2D resolutions of the synthetic aperture imaging lidar were analyzed. Because the nominal prototype of ideal rotation was difficult to implement, the translational motion was induced which would affect the envelope and phase of the synthetic aperture imaging lidar, leading to the defocus of the final images. Then the compensation method for the translation motion was given including envelope alignment and autofocus. Envelope alignment made use of the relativity of the pulse among the echoes, while autofocus made use of the phase of ideal rotation center to align the phase among the echoes. Finally, the block diagram, the work mode, the parameters design and the final effect image of imaging system were given, and the results with and without the translational motion compensation were compared.It proves the system validity and the necessity of the translational motion compensation.
出处
《红外与激光工程》
EI
CSCD
北大核心
2009年第4期637-641,共5页
Infrared and Laser Engineering
基金
国家863计划资助项目(2006AA12Z144)
关键词
激光雷达
合成孔径
转台成像
包络对齐
自聚焦
Lidar
Synthetic aperture
Imaging of rotating objects
Envelope alignment
Auto focus
