大气环境监测卫星作为国家民用空间基础设施规划中的科研卫星,其遥感应用需求对其载荷的定量化精度要求越来越重要.宽幅成像光谱仪作为大气环境监测卫星中的主要载荷,可获取光谱范围从可见光至长波红外(0.415~12.000 μm)的陆表和大气多光谱信息.采用45°扫描镜配合消旋系统的扫描方式,光路结构采用同轴望远镜系统,实现3个探测器焦面上21个谱段的同时对地的超宽幅高空间分辨率成像.为了准确地获取能量和仪器响应之间的定量关系,在卫星发射前开展宽幅成像光谱仪全光路、全口径辐射定标试验,分别介绍了可见到短波谱段积分球定标技术和中长波谱段热真空红外定标技术,为用户定量应用提供了良好的保障,并对定标过程中传递路径下的误差来源及精度进行分析评估.
As a scientific research satellite in the national civil space infrastructure planning,the quantitative development for the atmospheric environment monitoring satellite will be more and more important for the application of space remote sensing.As the main instrument for the atmospheric environment monitoring satellite,the wide-field imaging spectrometer can achieve the multi-spectral information about the land surface and atmosphere in the spectral range from visible light to long-wave infrared bands(0.415~12 μm).The 45° scanning mirror and racemic system is used for the scanning imaging,and the coaxial telescope system is applied to the optical structure to simultaneously obtain ultra-wide and high spatial resolution imaging from the ground with 21 spectral bands on the focal plane of the three detectors.To accurately obtain the quantitative relationship between the radiance and the instrument response,the full-optical path and full-aperture radiometric calibration tests are carried out for the wide-field imaging spectrometer before the satellite launches.The integrating sphere calibration in the visible short-wave spectrum and the vacuum infrared calibration in the medium and long wavelength bands are introduced,respectively,which provides a good guarantee for the quantitative application of users.During the calibration process,the error sources and calibration accuracy in the transfer path are analyzed and evaluated.