第6期
第18卷 2010年6月
文章编号
1004-924X(2010)06-1420-09
光学精密工程
Optics and Precision Engineering
星上CCD成像非均匀性的实时校正王文华1,2，何斌，韩双丽，李国宁1，吕增明"，任建岳（1.中国科学院长春光学精密机械与物理研究所，吉林长春130033；
2.中国科学院研生院，北京100039）
Vol. 18No.6
Jun.2010
摘要：研究了时间延时积分(TDICCD)成像产生非均勾性的原因，基于两点校正算法探讨了星上图像非均勾性实时校正的可行性方案。鉴于工程一体化设计的要求，在常用的CCD时序处理器FPGA上实现了硬件实时校正。通过对相机均匀辐射定标，利用FPGA读取前32行TDICCD图像数据进行非均匀性等效灰度值（NUEDN)计算，根据工程经验，设定当NUEDN>2时对数字图像进行非均匀性实时校正。硬件实时校正结果表明，均勾辐照下NUEDN可降至0.29。实
验室动态目标滚简成像试验表明，实时校正后TDICCD推扫成像均匀光滑，满足工程需要。关键调时间延时积分CCD；成像非均匀性;FPGA；两点校正法；辑款定标
中图分类号：TP391;TN386.5
文献标识码：A
doi; 10. 3788/OPE, 20101806. 1420
Real-timecorrectionofnonuniformityinCCDimagingforremotesensing WANG Wen-hua'-2, HE Bin', HAN Shuang-li',LI Guo-ning', LU Zeng-ming', REN Jian-yue
(l.Changchun Institute of Optics,FineMechanics and Physics, Chinese Academy of Sciences,Changchun130033,China;
2.GraduateUniversity of ChineseAcademy of Sciences,Beijing100039,China)
Abstract: The reasons for the nonuniformity in CCD imaging were researched, and the feasible schemes to correct the nonuniformity of an image from a satellite were discussed by using a flat field correction method. Then, based on FPGA-based processor, a real-time correction approach was pres-ented to control all of the operations of TDICCD to implement the hardware correction of the nonuni-formity. Furthermore, the Nonuniformity Equivalent Digital Number (NUEDN) was calculated by u-sing FPGA to extract the first 32 rows of a raw image in the uniform exposure, and the real time cor rection for digital images was carried out when the NUEDN was set to be more than 2. The experi mental results in the uniform exposure indicate that the NUEDN falls to O, 29. Dynamic push-scanning imaging test was also performed with a standard resolution chart attached on a roller, and the results have proved the validity of the approach in practical projects.
Key words: Time Delay Integrated CCD(TDICCD) ;imaging nonuniformity; FPGA; flat field correc-
tion; radiometric calibration
收稿日期：2009-06-18：修订日期：2009-08-26.
基金项目：国家863高技术研究发展计划资助项目(No.863-2-5-1-13B)