中文摘要：

针对地球敏感器的设计与仿真需求,研究了地球椭球成像、大气轮廓、晨昏线及背景星空成像,实现了高精度地球敏感器成像仿真;并在此基础上比较实验了圆拟合、椭圆拟合等不同地球边界拟合及地心检测算法的性能,根据系统在轨运行特点,提出了分步地球图像检测算法.一方面克服单纯圆拟合方法带来的地球扁率误差,另一方面利用轨道先验知识克服椭圆拟合过程中的长轴不稳定性.仿真实验证明,该方法有效地提高了敏感器检测精度及系统鲁棒性,并且时间复杂度低,满足在轨要求,能够有效促进各型地球敏感器的性能提升.

英文摘要：

An imaging simulation system of Earth Sensor is investigated, including the imaging of earth,atmosphere,twilight lines and background stars. To improve the simulation accuracy,the outline of earth is described as an ellipsoid rather than a sphere,and the scattering of atmosphere is taken into account. Based on the simulator,a hierarchical ellipse fitting algorithm is studied,in which the ellipse model is constructed to reduce the fitting error caused by the flat rate of earth,and the orbit a priori knowledge is used to improve the fitting robustness. Numerical simulations demonstrate the effectiveness of the approach proposed.