空间紫外遥感仪器光谱响应度定标环境的研究

Study on Calibration Environment of Spectral Responsivity for Space Ultraviolet Remote Sensing Instrument

为了减小空间紫外遥感仪器(SURSI)光谱响应度定标不确定度,实现SURSI在轨的高精度探测,对SURSI定标环境进行了深入的分析研究。利用光学薄膜的电磁场理论数值计算出铝+氟化镁膜在250～400nm波段,真空和大气两种环境下的反射率值并进行比对。通过构建SURSI真空/大气响应度比对测试研究系统,对SURSI整机光谱响应度在两种环境下的差异进行了实验研究,在250～400nm波段,平均偏差可达3.8%。理论分析及实验结果表明:受仪器内部光学元件铝+氟化镁膜光学性质的影响,SURSI光谱响应度在真空和大气不同环境下存在明显差异,且偏差值具有波长相关性,直接说明SURSI辐射定标在真空环境下完成的必要性。

Reducing the radiometric calibration uncertainty of the space ultraviolet remote sensing instrument （SURSI） in laboratory is very important to improve the instrument＇s detection accuracy in orbit. A deep study on the calibration environment of SURSI is made. The AI ＋ MgF2 film reflectivity of 250 - 400 nm in vacuum/air environment are calculated by the film electromagnetic theory and two results are compared. The experiment is completed, which is study on the discrepancy in the SURSI spectral responsivity when it is at different environments by establishing SURSI responsivity vacuum/air comparison system. The average deviation is about 3.8 % from 250 to 400 nm. Theoretical analysis and measurement result show that because they are affected by the optical properties of AI＋MgF~ film which are decided by optical components inside the SURSI, the spectral responsivities of SURSI have distinct difference in vacuum/air environment and the deviation depends on wavelength. It is necessary to make the radiation calibration of SURSI in vacuum environment.