基于天空光偏振特征的天文导航方式是最近发展起来的一种自动天文导航方式，其定位能力直接决定了它的发展应用价值.针对舰船偏振光天文导航方式，从天空光偏振角的探测模型和单天体天文定位的船位误差模型出发，建立了偏振光天文导航的误差模型.利用该模型，仿真计算分析了偏振光天文导航的定位能力.分析表明：当太阳位于探测装置的正横方向且天顶角较大时，探测到的天空光偏振角对太阳方向的变化最敏感，最有利于偏振光天文导航；当偏振角的测角准确度达到角分水平时，偏振光天文导航方式的自动定位准确度可达海里级，可用于辅助惯性导航.

Based on the polarization of skylight, the polarized light celestial positioning will have great application value when it has little position error. According to skylight polarization detection modle and single body celestial positioning modle, the polarized light celestial positioning error modle was built. Based on this model, the sensitivity of skylight polarization angle and sun direction was given, and the precision of polarized light celestial positioning was calculated. Analyzing results show that: 1)polarized light celestial positioning result will be better if the polarized direction detected on ship changes faster，so the detecting sensor can be set in the right direction according to the course, sun′s height and orientation; 2)the precision of polarized light celestial positioning system can reach NM level when the detecting precision of polarization angle achieves angle cent level.