光学学报, 2019, 39(7): 0728005, 网络出版: 2019-07-01

太阳漫射板反射率在轨衰退监测技术研究

On-Orbit Degradation Monitoring Technology for Solar Diffuser Reflectance
作者单位

1中国科学院安徽光学精密机械研究所通用光学定标与表征技术重点实验室, 安徽 合肥 230031

2中国科学技术大学, 安徽 合肥 230026

摘要
多通道扫描成像辐射计搭载于风云四号气象卫星上,为了使其实现高精度定量化遥感,其上配备了星上定标装置。该装置主要是引太阳漫射板(SD)反射的太阳光作为标准辐亮度源,太阳漫射板反射率衰减监测仪(简称比辐射计)定期监测漫射板反射率的变化。主要介绍了比辐射计的工作原理,并针对在轨返回的数据特点建立了太阳漫射板双向反射分布函数衰减因子计算模型。数据表明:比辐射计探测器受到了温度的影响,其不确定度为0.165%/℃,比值监测的方式消除了温度的影响。计算了3个通道衰减因子的合成监测不确定度,第一通道的合成监测不确定度为1.48%(k=2),第二、第三通道合成监测不确定度为1.16%(k=2)。结果表明:比辐射计可以实现漫射板反射率的衰减监测。
Abstract
A multi-channel scanning imaging radiometer is installed on the FY-4 meteorological satellite. To realize high-precision quantitative remote sensing, an on-board calibration device is provided. The device primarily uses a solar diffuser (SD) to reflect sunlight as a standard radiance source, and the solar diffuser reflectance degradation monitoring (SDRDM) device regularly monitors the reflectance variation of the SD. This study introduces the working principle of SDRDM and establishes a calculation model of the bidirectional reflectance distribution function (BRDF) degradation factor of the SD based on the characteristics of on-orbit data. The data show that the SDRDM device is affected by temperature and its uncertainty is 0.165% per ℃. The ratio monitoring method eliminates the influence of temperature. The combined monitoring uncertainties of three channels' degradation factors are calculated, which is 1.48% (k=2) for the first channel and 1.16% (k=2) for the second and third channels, respectively. These results suggest that the SDRDM device can effectively monitor the degradation of the SD's reflectance.
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