天体高度的获取精度是目前制约舰船自主天文定位精度的主要技术瓶颈，针对这一问题，提出了一种新颖的利用星光折射角和大气折射模型间接获取天体高度的方法。该方法通过两个星敏感器分别拍摄直射星图和折射星图，利用星图匹配与识别方法得到星光折射角；基于大气折射模型，根据测量得到的折射角精确获取天体高度值。仿真结果表明，当折射角测量精度为1″，观测高度约为6°的天体时，其天体高度的获取精度可达37″，相应的平均舰船定位精度约为23 m。对折射角测量精度、观测天体的高度和大气折射模型精度等因素对定位精度的影响进行了分析。

Positioning accuracy of vessel celestial navigation is limited by the low measurement accuracy of celestial altitude. For solving this problem, a novel method of celestial altitude determination is proposed. Refraction angles are obtained by two star sensors using a star pattern recognition method; the celestial altitudes are calculated accurately from the refraction angles according to the atmospheric refraction model. Simulation results show that the final vessel positioning accuracy can be better than 23 m under the conditions that the star sensor accuracy is 1″ and the observation altitude is about 6°. The effect of measurement accuracy of refraction angle, observation celestial heights and atmospheric refraction model accuracy on positioning accuracy is analyzed.