为了避开球面反射镜光谱反射率的测试难点,提出了间接平行光和直接发散光两种不同的定标方法标定仪器辐照度响应度。对两种方法的定标过程与其标定的响应度结果进行了比较与分析,相对偏差为1.0%。不确定度分析表明,利用250-400 nm间接平行光法的辐照度绝对定标不确度为±2.8%,相对不确定度为±2.0%;直接发散光法对应的不确定度分别为±2.4%和±1.4%,相对偏差均小于各自的相对定标不确度。结果表明,与间接平行光法相比,采用直接发散光法标定空间紫外遥感仪器(SURSI)辐照度响应度可以更有效地减少辐射定标不确定度。

In order to avoid the difficulty of testing the reflectance of spherical mirror,two methods to establish the SURSI irradiance calibration are introduced. One is the method by using indirect parallel light and the other method is by using the direct diverging light. Detail descriptions of calibration processes of the two methods and a series of comparison and analysis of the calibration results are given. The relative deviation of calibration results between two methods is 1.0%. The absolute uncertainty budget of the 250-400 nm spectral irradiance calibration using the parallel light method is ±2.8%,and the relative uncertainty budget is ±2.0%. The budgets using the diverging light method are ±2.4% and ±1.4%,respectively. The relative deviation value is less than that of any one of the two relative calibration uncertainties. The analysis result shows that the direct diverging light method to calibrate the space ultraviolet remote sensing instrument (SURSI) is more effective to reduce the radiometric calibration uncertainty compared with the indirect parallel light method.