为了满足无人飞行器自主导航对姿态参数提取的需求, 提出一种利用大气偏振模式稳定性分布的特征提取飞行器俯仰角和滚转角的方法.从刻画大气光学传输特性的Rayleigh散射理论出发, 建立了天空偏振光分布的理论和实测两种模式.利用优化算法, 从偏振信息中提取出导航用的天空特征点——太阳空间位置, 并利用太阳和天顶固定的时空关系, 获取天顶点位置信息.利用天顶点坐标建立姿态变换矩阵, 解算俯仰角和滚转角大小.通过模拟飞行器控制台, 利用理论和实测两种偏振模式数据分析验证, 解算的俯仰角均方根误差分别为0.002°和0.0031°, 滚转角均方根误差分别为0.0236°和0.0227°.该偏振方法获取姿态参数时计算简单, 解算精确度高.

To address the issue of attitude determination for the autonomous navigation of the unmanned vehicles, an approach to define the pitch and roll angle of the vehicle by means of the stable distribution of skylight polarization pattern was proposed. Firstly, based on the Rayleigh scattering theory, we establish the theoretical and practical detected patterns of the polarized skylight. Secondly, through optimization, we obtain the data of the astronomical marker—the location of the sun based on the polarization data detected. Then, with respect to the relatively consistent space-time relation between the sun and the zenith, the location of the zenith is thus figured out. Finally, the coordinate of the zenith is adopted to establish the attitude rotation matrix and by which to work out the pitch and roll angles. In addition, by setting up a simulation vehicle platform to acquire the theoretical and practical polarization data, the effectiveness of the approach is tested. The calculated root-mean-square errors of the pitch angle are 0.002° and 0.0031° respectively for the theoretical and practical simulation test, and errors of the roll angle are 0.0236° and 0.0227° respectively. The results show that the approach to attitude determination through polarization detecting has advantages in easy handling and high accuracy.