偏振导航的有效性在很大程度上依赖于能否从不同大气状况中获取到有效的全天空偏振分布信息。文中依据矢量辐射大气传输方程仿真分析了无云晴空和混浊大气状况下的全天空偏振度和偏振角分布特征, 并研究了大气混浊度、太阳方位、观测高度和观测波段对偏振分布的影响, 进而探讨了不同大气状况下偏振导航的有效性。结果表明: 太阳位置决定了全天空偏振分布图景的整体形式; 混浊大气对近地层观测偏振信息的影响明显, 当整层光学厚度增大至2以上时, 偏振度将降低至0.1以下, 此时偏振信息的检测难度增大, 不利于导航, 而以晴空为主的中高层大气受混浊大气影响较小, 偏振信息稳定, 且符合Rayleigh单次散射分布特征, 可保证白天全时段导航的有效性; 在无云大气下, 可见光波段内长波段更适合作为偏振导航的观测波段。

The effectiveness of polarization navigation depends heavily on the ability to derive effective all-sky polarization distribution information from different atmospheric conditions. Based on the simulation of vectorial atmospheric transport equation, the properties of all-sky distribution of degree and angle of polarization under cloudless clear and turbid atmosphere were analyzed, and the effects of different atmospheric turbidity, solar orientation, observed altitude and observed band on the polarization distribution were studied, and then the effectiveness of polarization navigation under different atmospheric conditions was discussed. The results show that the solar orientation determines the overall pattern of the all-sky polarization information. The turbid atmosphere has obvious influence on the polarization information of the near ground. When the whole layer of the optical thickness increases to more than 2, the degree of polarization will be reduced to below 0.1, in this case, the detection of the polarization information becomes more difficult, and not conducive to the navigation. While the middle and upper atmosphere dominated by clear skies are less affected by turbid atmosphere, the distribution of polarization information is stable and in accordance with the distribution of Rayleigh single scattering, which can ensure the effectiveness of navigation during the daytime. And the long waveband is more suitable as the observation band for polarization navigation within the limits of visible band under cloudless clear atmosphere.