为了研究地球反照的可见光对太阳电池阵电流在卫星陨落期间的影响程度, 进行阵电流的地球反照系数估计。以运行在300 km高度、降交点地方时约10: 30AM的某太阳同步轨道近地卫星陨落为例, 在讨论卫星轨道半长轴、倾角、光照角、降交点地方时等参数漂移的基础上, 重点分析卫星太阳电池阵电流和温度的变化, 并对电流进行正弦曲线拟合, 进而建立地球反照系数的估计模型, 最后用卫星陨落期间的遥测数据进行检验。结果表明, 卫星自300 km轨道高度向100 km轨道高度陨落期间, 地球反照系数先由0.21逐渐变大, 最大值接近0.40, 后又逐渐变小至0.20附近; 对估计值的二次曲线拟合结果表明, 在轨道高度210~270 km这一区间, 地球反照对于太阳电池阵的作用最强, 对应的地球反照系数极大值约为0.28, 作用最强的中心区域可能在250 km轨道高度附近。估计结果可应用于在轨航天器长期管理的遥测诊断、能源估计与预测、器件健康状态评估以及可见光载荷应用等方面。

In order to estimate the albedo coefficient of the Earth, one needs to investigate the change in solar array output current of a low Earth orbit (LEO) satellite caused by the sunlight reflected from the Earth while the satellite is falling to the ground. An LEO satellite orbiting along a sun-synchronous orbit at an altitude of 300 km with a local time of descending node (LTDN) of 10: 30 A.M. is selected as the sample. Details of the semi-major axis degradation, inclination perturbance, solar incidence variation, and LTDN shift are discussed, and the solar array output current and temperature are analyzed. Based on the sinusoidal fitting of the solar array output current data, a method for estimating the albedo coefficient of the Earth is developed. The results, validated by telemetry, indicate that when the satellite falls from an altitude of 300 km to 100 km, the albedo coefficient of the Earth increases gradually from 0.21 to 0.40, and then decreases to approximately 0.20. Parabolic fitting of the estimated results indicate that for orbits at altitudes in the range 210-270 km, the albedo coefficient of the Earth results in an enhanced solar array output current, with the maximum occurring for an orbit at an altitude of approximately 250 km when the albedo coefficient of the Earth is approximately 0.28. The results will be helpful for telemetry diagnosis, energy estimation and prediction, and device state of health evaluation for long-term management of satellites for tracking, telemetry, and command, and visible light payload applications.