“嫦娥二号”卫星CCD立体相机的关键技术

Key Technologies of CE-2 CCD Stereo Camera

文章介绍了中国两次绕月探测中CCD立体相机所采用的技术与创新,并与国际同类相机所获取的图像进行了比较;在此基础上详细介绍了"嫦娥二号"(CE-2)卫星CCD立体相机的综合创新集成技术——"单镜头两视角同轨立体成像、时间延迟积分图像传感器(TDICCD)推扫、速高比补偿",并从工程目标与科学目标出发进行探测灵敏度及成像动态范围的需求分析;根据需求分析确定了总体技术方案,包括光、机、电的优化设计以及对月探测中首次采用TDICCD的技术困难与对策;特别讨论了速高比补偿的方案及实施途径,并进行了在轨试验验证。文章最后分别给出了虹湾地区成像分辨率为1.3m以及全月面分辨率为7m的代表性图像,图像清晰、层次丰富,显示出中国在对月立体成像技术上取得了显著进步。

The paper describes the CCD-stereo camera＇s novel techniques used in China＇s two around-lunar reconnaissances and compares similar images of lunar terrain obtained by foreign cameras. The paper also details CCD stereo-camera＇s overall scheme, i.e. synthetically integrating techniques of ＂same orbit stereo-imaging with two sight angles, TDICCD pushing scan and velocity/height ratio compensation＂ . It in- cludes the requirement analysis of the sensibility and imaging dynamical range for the sake of engineering and science goals. The overall scheme is established on the basis of the requirement analysis, including the optimizing designs with optics, machine and electronics and imaging capability analysis for this scheme. The scheme can fulfill the mission goals. The paper introduces the technical difficulties with time-delay-integration CCD for lunar high resolution stereo-imaging and the countermeasures employed, especially discusses the scheme and way for velocity/height ratio compensation and gives the executed validation on orbit. Finally, it shows several clear images of Iridum area with resolution of 1.3m and of global lunar images with resolution of 7m. The results indicate that these techniques employed are effective, and China has reached international ad- vanced level： the global lunar images with 7m GSD are of the highest resolution in the world and represents the obviously progress in the stereo-camera techniques for lunar reconnaissance.