星敏感器作为一种被广泛应用于各种载体上的高精度自主导航定位设备，探测灵敏度影响着其工作效率及测量精度。与航天器载体上的星敏感器不同，船用星敏感器工作在海平面环境下，其探测灵敏度不仅由镜头及成像传感器的各项参数决定，还要受到夜空背景以及大气透射等外部因素的影响。为了给船用星敏感器的研制与应用提供理论依据，通过对星光传播、传感器成像以及信号提取过程的研究分析，推导出了船用星敏感器探测灵敏度的计算模型，并通过实验验证了该模型的有效性，在此基础上，分析了各项因素对船用星敏感器探测灵敏度的影响情况，根据分析结果对船用星敏感器系统的设计研制提出了相应建议。

As an accurate independent navigation equipment, star sensor is widely used on different kinds of platform. The detection ability directly influences the efficiency and measurement accuracy of the star sensor. Shipboard star sensor works on the sea, which is different from the space, the detection ability is influenced not only by the parameters of the lens and the image sensor, but also by the night sky background and the atmosphere. In order to provide theoretical basis for research and application of shipboard star sensor, a calculation model of the detection ability for shipboard star sensor is deduced according to the study and analysis of star light propagation, imaging and signal extraction process, and the correctness of the model is verified by experiment. All the influencing factors are analyzed with the model. In the end, several suggestions on design and development of shipboard star sensor are proposed based on the analysis results.