起始波长误差对合成孔径激光雷达成像的影响  

Influence of starting wavelength error on imaging of SAL

作　　者：王亚许 张艳 张蓉竹[1] WANG Ya-xu;ZHANG Yan;ZHANG Rong-zhu(College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, China;School of E lectronic and Communication Engineering,Guiyang University,Guiyang 550005 ,China)

机构地区：[1]四川大学电子信息学院,四川成都610064 [2]贵阳学院电子与通信工程学院,贵州贵阳550005

出　　处：《光电子．激光》2018年第5期479-484,共6页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61505036);贵州省科技厅基金项目(黔科合J字[2015]2009号)资助项目

摘　　要：合成孔径激光雷达采用的可调谐激光器通常不够稳定,导致存在起始波长误差。本文研究可调谐激光器起始波长误差对合成孔径激光雷达成像的影响。建立了具有起始波长误差的可调谐激光器输出信号经合成孔径激光雷达系统后的成像模型,利用Matlab进行模拟仿真,详细讨论了起始波长误差对合成孔径激光雷达在方位向和距离向成像的影响。结果表明,起始波长误差对合成孔径图像的距离向分辨率没有影响,但是恶化了方位向成像质量。起始波长误差对方位向成像的主瓣强度影响不大,主要影响了点目标的旁瓣从而造成方位向成像质量恶化。起始波长误差在(0,2λ_c)和(0,λ_c)内服从均匀分布时主瓣宽度分别约为理想情况下的2倍和1.5倍;起始波长误差在(0,0.1λ_c)内服从均匀分布时,对主瓣宽度的影响可以忽略,对旁瓣仍有较明显的影响;起始波长误差在(0,0.02λ_c)内服从均匀分布时,对旁瓣的影响可以忽略。可调谐激光器起始波长为1 550nm时,起始波长误差控制在0.02个波长,方位向成像的质量比较高。对起始波长误差恶化方位向分辨率的本质进行了探讨,得出起始波长误差恶化方位向分辨率的本质是导致了多普勒频率的非线性。The tunable source used in the synthetic aperture laser（SAL）radar is not sufficiently stable while stable sources are not broadly tunable,leading to the fluctuations in the wavelength at the start of the scan,namely the starting wavelength error.In this paper,the effect of the starting wavelength error of the tunable source on the imaging of SAL is studied.An imaging model of tunable laser output signal with starting wavelength errors is established.The simulation is carried out using MATLAB.The results show that the starting wavelength error deteriorates the azimuth imaging but has no effect on the range resolution.The starting wavelength error has little effect on the main lobe amplitude of the azimuthal imaging.The main lobe is 2 times and 1.5 times of the ideal main lobe under uniform distributions of（0,2λc）and（0,λc）respectively.When less than（0,0,1λc）,the effect of the main lobe width can be negligible.There is still a significant effect on the side lobe.If less than（0,0.02λc）,the effect on the side lobe can be negligible.Furthermore,the nonlinearity of Doppler frequency caused by starting wavelength error is the reason that the azimuth imaging is deteriorated.

关 键 词：合成孔径激光雷达 可调谐激光器 起始波长误差 成像质量 非线性 

分 类 号：TN253[电子电信—物理电子学]