环境减灾二号A/B卫星在轨定标模式设计与验证

Design and Validation of HJ-2A/B Satellites On-orbit Radiometric Calibration Mode

环境减灾二号A/B(HJ-2A/B)卫星上搭载了16 m相机、大气校正仪、高光谱成像仪和红外相机4台有效载荷,主要执行中等分辨率下的800 km大幅宽对地观测和定量化遥感任务,因此高精度的辐射定标对环境减灾二号A/B卫星的数据处理和应用至关重要。为了保证4台成像体制各不相同的载荷能够满足在轨长期稳定的辐射响应精度,文章介绍了卫星对日定标、对月定标、偏航定标、载荷内定标等各种在轨辐射定标模式的设计方法,通过卫星获取的在轨定标遥测和图像数据,分析了卫星发射入轨后各种定标模式下遥测及相关定标数据。结果表明:各类型在轨辐射定标模式可以有效实现对4台载荷的辐射定标,获取的高质量辐射定标数据可以满足各载荷在轨长期稳定运行的辐射定标需求,可为后续光学遥感卫星在轨辐射定标设计提供参考。

HJ-2A/B satellites have four payloads:16m camera,PSAC(polarized scanning atmospheric corrector),hyper-spectral imager,infrared camera,and have the capability of middle space resolution and 800km swath width,and take missions of quantitative remote sensing.Therefore,the radiometric accuracy of each payload is significant for data process and appliance.In order to satisfy the radiometric accuracy stability for these four different imaging systems in long on-orbit term,various radiometric calibration modes,such as sun-oriented calibration mode,moon-oriented calibration mode,90°yaw calibration,and payload self-calibration mode,designed for HJ-2A/B satellites are introduced,and the telemetry and calibration data obtained by HJ-2A/B satellites on-orbit are analyzed.As a result,these designed radiometric calibration modes can be effectively used in on-orbit test,and monitor the long-range radiometric accuracy stability of four remote sensing payloads.Meanwhile,the design of these on-orbit radiometric calibration modes can also provide reference for other optical remote sensing satellites.