紫外高光谱探测仪实验室辐照度定标研究

Laboratory Irradiance Calibration of Spaceborne Ultraviolet Hyperspectral Atmospheric Spectrometer

紫外高光谱探测仪在轨运行时通过地球光观测光路和太阳光观测光路获取辐射和光谱信息,因此在发射前需对载荷进行实验室定标。定标后获取的辐照度定标系数将用于在轨计算获取反演所需的太阳参考谱,定标精度直接影响仪器在轨探测及数据反演精度,决定着获取的遥感信息的可靠性。采用直接发散光辐照度定标方法,搭建二维定标平台对定标光路进行不同角度、距离的标准灯测试,将三个距离下的实验值借助最小二乘法线性拟合得到辐照度定标系数,并对系数进行角度等因素的校正。测试结果表明合成不确定度为3.42%,符合辐射定标要求,表明了方法的可行性。

When the spaceborne ultraviolet hyperspectral atmospheric composition spectrometer is in orbit,it obtains radiation and spectral information through the light path of the earth light observation as well as the light path of the sunlight observation,so it is necessary to be calibrated in the laboratory before launching.As the irradiance calibration coefficient will be used for obtaining the solar reference spectrum during the on-orbit observation,the calibration accuracy directly affects the instrument′s on-orbit detection and inversion accuracy,and determines the reliability of remote sensing information.The direct diverging light is used in the irradiance calibration method,and a two-dimensional calibration platform is build to carry out a series of tests at different angles and distances on the calibration light path.By using the least squares method to linearly fit the experimental values at three distances,the irradiance calibration coefficient is obtained,and then the influence of the angle and the other factors is corrected.The calibration results show that the combined uncertainty is 3.42%,which meets the requirements of radiation calibration,indicating the feasibility of the method.