摘要
激光的单色性和自然图像频谱稀疏且集中在低频区间的特点,使图像频谱稀疏采样成像成为可能.基于小规模激光探测器,引入参考激光,本文提出了频域稀疏采样激光成像方法.介绍了频域稀疏采样激光成像的原理和成像系统结构,推导了激光回波重构复频谱的表达式,给出了重构频谱和复图像的仿真结果并分析了信号参数对重构效果的影响,同时采用相干系数、均方误差和结构相似度来评价其重构效果.规模为256×256的激光回波复图像仿真表明,5个拼接1/4×1/4规模频域探测器组成的近似十字型稀疏采样结构,在约31.25%(5/16)的频域稀疏采样条件下,仍可获得较好的重构频谱和重构复图像.
The monochromaticity of the laser and the characteristics of the natural image’s spectrum,including sparsity and concentrating in the low frequency range,make it possible to sample the image spectrum sparsely.Based on small-scale laser detectors and the introduced laser reference signals,a method of laser imaging with sparse sampling in frequency domain is proposed in this paper.The principle of frequency sparse sampling laser imaging and the imaging system structure are introduced.The simulation results of spectrum and complex images reconstructed are given.Both the effects of the signals’parameters,such as the ratio of the reference laser signal amplitude to the laser echo spectrum amplitude and the initial phase of the laser reference signal,on reconstruction results are investigated.The reconstruction results are evaluated by correlation coefficient,mean square error(MSE),and structural similarity index(SSIM).For the strong correlation between phase and amplitude of the laser echo complex image,the amplitude image and the phase image are both set to be 256×256 diagram.The sparse laser detector plane array consists of 564×64 frequency domain laser detector arrays,which form a cross and make a sparsity rate of 31.25%(5/16).The simulation results show that the correlation coefficient,MSE and SSIM of the spectrum reconstructed are 0.96,22.14,1.00 and those of the complex image reconstructed are 0.96,1857.25 and 0.67 respectively.The simulation results indicate that the method proposed is effective.However,the method requires the laser reference signal amplitude to be about 30 times the mean value of the laser echo spectrum amplitude,which reduces the dynamic range of the detectors.The initial phase of the laser reference signal has no obvious effect on the reconstruction results.
作者
崔岸婧
李道京
吴疆
周凯
高敬涵
Cui An-Jing;Li Dao-Jing;Wu Jiang;Zhou Kai;Gao Jing-Han(Key Laboratory of Science and Technology on Microwave Imaging,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第5期385-391,共7页
Acta Physica Sinica
基金
中科院重点部署项目(批准号:E03701010F)资助的课题。
关键词
激光成像
频域稀疏采样
激光探测器
图像重构
laser imaging
sparse sampling in the frequency domain
laser detector
image reconstruction
