摘要
空间光学遥感器辐射定标包括发射前实验室辐射定标和在轨辐射定标。中国空间光学遥感器寿命由最初2~3年已延长到8~10年,需要建立在轨辐射定标系统。文章在总结美国、法国、英国同类相机在轨辐射定标方法的基础上,结合中国漫反射板研制基础及工程实现能力,以某项目需求为背景,提出了大视场可见–近红外空间相机全光路全视场全口径在轨辐射定标方法。星上定标系统由漫反射板、稳定性监测比辐射计组成。漫反射板置于入光口前,定标时刻漫反射板展开后,太阳照亮漫反射板形成已知光谱辐亮度的近似朗伯面光源,直接实现空间光学遥感相机全孔径、全光路和全视场的星上辐射定标;稳定性监视比辐射计用于漫反射板星上稳定性监视及其双向反射分布函数（BRDF）修正,确保长期在轨运行过程中空间光学遥感相机的数据产品的绝对辐射定标精度。经过分析,该方法下相机绝对辐射定标精度优于5%。
Space optical remote sensor radiometric calibration includes pre-launch in-laboratory radiometric calibration and in-orbit radiometric calibration. The lifetimes of Chinese space optical remote sensors have increased from initial 2~3 years to 8~10 years. It is required to establish an in-orbit radiometric calibration system. On the basis of summarizing radiometric calibration methods for similar cameras in the United States, France and Britain, in combination with the development foundation and engineering capability for diffuse reflection plate in China and by talking a certain project＇s needs as background, this paper proposes an in-orbit radiometric calibration method in the form of all bore, full FOV and full optical path for near infrared space camera with large FOV. The onboard radiometric calibration system consists of a diffuse reflection plate and a stability monitoring ratio radiometer. The diffuse reflection plate is placed in front of entrance. When the plate deploys during calibration, the sun illuminates the plate, and then an approximate Lambertian surface light source with known spectral radiance is formed, so as to direct carry out the radiometric calibration in the form of all bore, full VOF and full optical path. The stability monitoring ratio radiometer is used to monitor the stability of the diffuse reflection plate and make its BRDF correction onboard, to ensure absolute accuracy of data products of space optical camera in long-term in-orbit operation. Through analysis, the absolute radiometric calibration accuracy of this method is better than 5.0%.
出处
《航天返回与遥感》
北大核心
2016年第2期92-99,共8页
Spacecraft Recovery & Remote Sensing
基金
科工局"十二.五"民用航天预研项目(D030101)
关键词
大视场
全光路
全视场
全口径
在轨辐射定标
空间光学遥感器
large field
all-optical path
full field
full bore
in-orbit radiometric calibration
space optical remote sensor
