光学拼接焦平面空间相机的相对辐射定标

Relative Radiometric Calibration for Space Camera with Optical Focal Plane Assembly

为了提高光学拼接焦平面空间相机的成像性能和图像质量,开展了空间相机研制全过程的辐射定标技术研究,包括辐射响应性能分析、图像传感器的辐射定标及筛选、焦平面辐射定标、系统级辐射定标以及辐射定标数据应用等,并对具有反射镜光学拼接焦平面的空间相机进行了辐射定标实验。结果表明,利用相对辐射校正系数对图像校正,可以有效消除渐晕,图像的非均匀性由14.1%降至0.4%,图像质量明显提升;图像传感器的筛选以及焦平面组件的辐射定标,减少了图像传感器之间的辐射响应差异,相对定标不确定度小于1.0%。

In order to improve the imaging performance and image quality of space cameras with an optical focal plane assembly,the radiometric calibration researches in the whole develop process of the space cameras are conducted which include the radiation response performance analysis,the radiometric calibration and screening of the image sensors,the focal plane radiometric calibration,the system-level radiometric calibration,and the applications of radiometric calibration data.The radiometric calibration experiment is conducted for the space cameras with a reflector-based mosaic focal plane.The results show that the vignetting can be effectively eliminated when the image is corrected by using the relative radiometric correction coefficient,and the nonuniformity of the image decreases from 14.1% to 0.4% with an obvious enhancement in the image quality.Moreover,the radiometric response difference between the image sensors is reduced by utilizing the screening of the image sensors and the radiometric calibration of focal plane components,and the relative calibration uncertainty is less than 1.0%.