Solar panels can also be used as coarse sun sensors to increase the pico-satellite system’s redundancy and reliability. This flexible setup is easily sensitive to surrounding light sources as it sees the whole sky, so with the interference of Earths albedo light, it does not show a high accuracy. To improve the performance of satellite attitude measurement in this specific situation, a modified attitude determination method was investigated. According to the actual output of solar panel with the interference of albedo light, the Wahbas problem was re-discussed, and a new loss function for optimal attitude determination was proposed. Also the method to solve the optimal weighted leastsquare function was developed. From simulation, compared with the classic quaternion estimator (QUEST), which is based on Wahbas loss function, the suggested attitude determination method, which is based on the new loss function, shows higher accuracy. Monte Carlo simulation shows that the average attitude error of the suggested method is 17% lower than QUEST, and the standard deviation is 57% lower as well．
［1］ HEIDT H, PUIGSUARI J, MOORE A S, et al. Cubesat: a new generation of picosatellite for education and industry lowcost space experimentation ［C］∥ 14th Annual AIAA/USU Conference on Small Satellites. Logan, Utah, USA: AIAA/USU, 2000: 113116．
［2］ 刘建业,段方,李丹,等.基于太阳电池板与磁强计的小卫星姿态确定算法研究［J］.宇航学报,2007,28(1): 218222.
LIU Jianye, DUAN Fang, LI Dan, et al. An algorithm for microsatellite attitude determination using solar panels and magnetometer ［J］. Journal of Astronautics, 2007,28(1): 218222．
［3］ APPEL P. Attitude estimation from magnetometer and earthalbedocorrected coarse sun sensor measurements ［J］. Acta Astronautica, 2005, 56(1/2): 112．
［4］ SHUSTER M D, OH S D. Threeaxis attitude determination from vector observations ［J］. Journal of Guidance, Control, and Dynamics, 1984,4(1): 7077．
［5］ MARKLEY F L. Attitude determination using vector observations: a fast optimal matrix algorithm ［J］. Journal of the Astronautical Sciences, 1993,41(2): 261280．
［6］ MORTARI D. ESOQ: A Closeform solution to the Wahaba problem ［J］. Journal of the Astronautical Sciences, 1997,45(2): 159204．
［7］ MORTARI D. Second estimator for the optimal quaternion ［J］. Journal of Guidance, Control, and Dynamics, 2000,23(1): 885888．
［8］ WAHBA G. A leastsquare estimate of satellite attitude ［J］. SIAM Review, 1965,7(3): 409．
［9］ 赵翔宇,金小军,韩柯,等.皮卫星电源系统的设计与仿真［J］.浙江大学学报:工学版,2009,43(2):228233．
ZHAO Xiangyu, JIN Xiaojun, HAN Ke, et al. Design and simulation of the power system of picosatellite ［J］. Journal of Zhejiang University: Engineering Science, 2009,43(2): 228233．
