风云四号是地球静止三轴稳定平台气象卫星,装载其上的辐射成像仪受剧烈的外热流日周期和年周期变化的影响, 扫描机构和主光学系统等关键部件的温度每天波动可达40℃以上.光学及支撑结构如何适应剧烈的环境温度变化, 并保证良好的像质, 是地球静止三轴稳定平台遥感仪器系统设计的国际性难题.多种特性材料的匹配性设计以及适当支撑结构形式的采用,是避免和减少因温度大幅波动引起的光机变形及成像质量下降的良好策略.在轨数据表明, 辐射成像仪克服了昼夜温差大的不利影响, 敏感恒星时的弥散斑几乎仅覆盖一个像素, 而且正午和子夜结果差别不大.

FY-4 is a geostationary three-axis stable platform meteorological satellite. The radiation imager loaded on it is affected by the dramatic daily and periodic changes of the external heat flow. The temperature of key components such as the scanning mechanism and the main optical system fluctuates over 40°C per day. How the optical and supporting structures adapt to severe environmental temperature changes and ensure good image quality is an international problem in the design of remote sensing instrument systems for geostationary triaxial stabilization platforms. The matching design of various materials and the adoption of appropriate supporting structure forms are good strategies to avoid and reduce the deformation of the optical machine and the degradation of imaging quality caused by large temperature fluctuations. The on-orbit data indicates that the radiation imager overcomes the adverse effects of large temperature difference between day and night. The diffuse plaques of sensitive stars cover only one pixel, and the noon and midnight results are not much different.