摘要
由于多相位TDI CCD行间电荷转移引起的像移无法通过光、机、电等方法消除,本文研究了电荷转移对遥感相机成像质量的影响。首先,介绍了推扫式遥感相机的工作原理与前向像移补偿方法。接着根据TDI CCD行间电荷的转移方式,利用脉冲传递函数建立了电荷转移速度模型,并对TDI CCD电荷转移速度与景物像点移动速度进行了比较分析,揭示了TDI CCD电荷转移像移产生的原因。然后,建立了多相位TDI CCD电荷转移像移的调制传递函数,定量给出了二、三、四相位TDI CCD电荷转移像移引起的空间频率对比度损失。最后,搭建测试平台,采用胶片式遥感相机获取了奈奎斯特频率处的靶标图像,其分辨率为60lp/mm,并比较了三、四相位TDI CCD电荷转移像移对靶标分辨率的影响。实验结果表明,提出的电荷转移像移模型与图像实验仿真结果相吻合。
The smear caused by a charge transfer for multi-phase TDI CCD in a remote sensing system couldn＇t be eliminated by the motion compensation methods.First,the operation principle and forward motion compensation method are introduced.Then,according to the charge transfer mode of a TDI CCD,the velocity model of charge transfer in one line period is developed by employing an impulse function,velocities of image point and TDI CCD are analyzed,and why the charge transfer causes the smear is also presented.Furthermore,the Modulation Transfer Function of charge transfer smear existed in a multi phase TDI CCD is developed,and the contrasts of spatial frequency losses due to charge transfer smear for two,three and four phase TDI CCDs are illustrated.Finally,an image quality evaluation platform is established,an image drone with a resolution of 60 lp/mm is captured by a film aerial camera at Nyquist frequency,and effects of charge transfer smear on image quality for two,three and four phase TDI CCDs are studied,respectively.The results confirm that the proposed charge transfer model accords well with the experiment.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2011年第10期2500-2506,共7页
Optics and Precision Engineering
基金
国家863高技术研究发展计划资助项目(No.2006AA06A208)
国家重点基础研究发展规划项目(No.2009CB72400102A)
