光学学报, 2020, 40(20): 2029001, 网络出版: 2020-10-01

GF-5全谱段光谱成像仪星上定标组件在轨性能评价

On-Orbit Performance Evaluation of On-Board Calibration Component of GF-5 Visible and Infrared Multispectral Imager
作者单位

1中国科学院通用光学定标与表征技术重点实验室, 安徽 合肥 230031

2北京空间机电研究所, 北京 100094

摘要
介绍了高分五号全谱段光谱成像仪(VIMI)可见近红外波段星上定标组件的组成和工作方式,分析了VIMI发射后星上12次太阳漫反射板(SD)双向反射分布函数(BRDF)的量值衰减情况。对比SD反射率衰减监测仪(SDRDM)长期观测的太阳数据表明,不同监测波段探测器的衰减程度不同,其中900 nm监测波段的硅探测器衰减最大,约为4.3%。当入射角与观测方位夹角接近时,SD BRDF的衰减因子(H因子)变化很小。根据H因子的物理模型得到SDRDM实际监测的测量不确定度小于0.86%,满足小于1.5%的指标要求,且VIMI星上定标组件全寿命期输出光谱的辐亮度不确定度小于3.4%。
Abstract
In this paper, the composition and working mode of the on-board calibration component on the visible and near infrared band of GF-5 visible and infrared multispectral imager (VIMI) is introduced. The attenuation of on-board 12-time solar diffuser (SD) bidirectional reflection distribution function (BRDF) on the satellite after VIMI launch is analyzed. Comparing the long-term solar data observed by SD reflectance degradation monitor (SDRDM) shows that the attenuation degree of different monitoring band detectors is different. Among them, the 900 nm monitoring band silicon detector has the largest attenuation, about 4.3%. When the incident angle is close to the observation azimuth, the attenuation factor (H factor) of SD BRDF changes little. According to the physical model of the H factor, the measurement uncertainty of actual monitoring by SDRDM is less than 0.86%, which meets the index requirement of less than 1.5%, and the radiance uncertainty of the output spectrum of the calibration component on the VIMI satellite is less than 3.4% during the lifetime.
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