静轨紫外可见高光谱探测仪星上外定标方案

External calibration methods for geosynchronous ultraviolet-visible hyperspectral instrument

紫外可见高光谱探测仪搭载于地球同步轨道卫星,具备高时间分辨率、高光谱分辨率、长寿命周期等特点。研究其星上外定标方案,消除内定标装置衰减等变化带来的影响,是实现遥感器在轨高精度定标或检校的重要手段。本文结合静止轨道卫星的特点,建立了紫外可见高光谱探测仪辐射特性分析流程,比较了不同外定标方案的特点及它在地球同步轨道卫星上的可行性,提出并分析了一种采用太阳定标、月球定标和恒星定标相结合的高光谱探测仪在轨绝对辐射定标方案。定标不确定度分析表明,太阳定标不确定度为3.6%,恒星定标不确定度为3.87%,基于月球定标漫反射板监测不确定为3.55%,满足在轨定标要求。

A geosynchronous ultraviolet-visible hyper-spectral instrument(GUVI)is deployed into a geo⁃synchronous Earth orbit(GEO).The GUVI has high temporal and spectral resolution as well as a long lifespan.Accordingly,the research into in-orbit calibration methods is crucial to eliminating the influence of attenuation on the precision of the internal calibration device.Consequently,highly precise calibration of orbiting sensors was achieved;this ensured that GUVI remained reliable in orbit.Solar,lunar,and stellar calibration along with a GEO were proposed based on the simulation.Then an absolute in orbit radiomet⁃ric calibration comprising solar and stellar calibration was proposed;the diffuser monitor was based on lu⁃nar calibration.Thus,an external calibration program was determined.Further,the corresponding equa⁃tions were formulated considering the signal-to-noise ratio of stellar calibration.Finally,the uncertainties of solar,lunar,and stellar calibrations were computed as 3.6%,3.87%,and 3.55%,respectively,thus meeting the requirements of on-orbit calibration.