宽视场空间光学相机星上相对辐射定标系统

The Spaceborne Relative Radiation Calibration System of Large Field Space Optical Camera

星上相对定标已成为在轨辐射定标链中的重要环节。星上相对定标系统采用LED作为定标光源,在完成LED空间适用性的研究基础上,对定标光源的老炼和筛选方法进行了描述,重点介绍了星上相对定标系统的组成、非均匀照明的定标工作原理,并针对宽视场空间光学相机开展了在轨定标测试与验证试验。对星地间定标图像数据进行比对,并给出了各像元的校正因子。该星上定标系统具有较强的空间适应性,综合不确定度为2.9%,能够满足宽视场空间光学相机星上相对辐射定标要求。

Spaceborne relative calibration has become an important link in the course of optical camera’s on-orbit radiation calibration. A spaceborne relative calibration system is introduced and LED is selected as light source. LED’s seasoning and screening methods are described on the basis of analyzing LED’s applicability in space optical camera’s calibration, then the system composition and operational principle of nonuniform illumination is emphatically introduced, and a large field space optical camera’s on-orbit radiation calibration and verification experiment is carried out based on the spaceborne relative calibration system. The difference between on-orbit calibration data and on-ground calibration data is analyzed, and pixels’ correction factors are given. The spaceborne relative radiation calibration system has wonderful space applicability and the calibration uncertainty is 2.9%, so it can satisfy the requirement of the large field space optical camera’s spaceborne relative calibration.