由于FY-3(01)星和FY-3(02)星宽视场扫描式太阳辐射监测仪(SIM)测量时间短、精度低, 本文利用FY-3(03)星SIM实现了太阳的高精度跟踪测量。首先, 分析了SIM太阳跟踪精度指标、跟踪转动范围, 测试并确定了数字太阳敏感器(DSS)的视场范围、频率、分辨率, 标定了DSS在轨像面辐照度。为消除跟踪抖动现象, 分析测试了控制时间间隔和跟踪精度的关系, 确定了理想控制时间间隔为500 ms。外场和在轨实验结果表明, SIM太阳跟踪精度优于±0.1°, 俯仰在轨跟踪精度为0.029°, 偏航在轨跟踪精度为0.025°, 原始太阳总辐照度(TSI)值为1 353.1 W/m2。另外, DSS太阳指向精确, 跟踪控制可靠, 大幅增加了TSI监测时间。FY-3(03)星SIM在太阳同步轨道卫星上实现了TSI的太阳跟踪测量, 跟踪精度是国际空间站(ISS)同类载荷CPD跟踪精度的10倍。

As wide-field scanning solar irradiance monitors (SIMs) on the FY-3(01) satellite and FY-3(02) satellite have short measuring time and low accuracy, the high precision sun-tracking measurement of the SIM on the FY-3(03) satellite was explored. Firstly, the sun-tracking accuracy and the rotation angle of the SIM were analyzed, the field of view, frequency and the resolution of the Digital Sun Sensor (DSS) were tested and determined, and the on-orbit image irradiance of the DSS was calibrated. In order to eliminate the jitter tracking, the relationship between the control interval and the tracking accuracy was analyzed, and the ideal control interval was determined to be 500 ms. The experiment on ground and on-orbit show that the sun-tracking accuracy of SIM is better than ±0.1°, the pitch on-orbit tracking accuracy, yaw on-orbit tracking accuracy are 0.029°and 0025°, respectively, and the original TSI value measured successfully by the SIM is 1 353.1 W/m2. Moreover, the DSS shows an accurate sun pointing and reliable sun-tracking control, by which the measurement time of TSI is increased significantly. The experiment shows that the SIM on the FY-3(03) satellite implements the sun-tracking measurement on the sun synchronous satellite, and the tracking accuracy is about 10 times that of the similar payload CPD on International Space Station (ISS).