导航星目标的提取是近红外天文导航中的关键步骤，直接关系到后续的星目标识别和星图匹配。由于天光背景很强，提取星目标极为困难。近红外天文导航在近红外波段对恒星进行检测，即使在白天也可获得足够多用以导航的恒星目标。在分析近红外星图图像特点的基础上，引入能量投影，根据投影峰值确定潜在恒星目标和噪声点的位置；然后根据能量变化，设定待处理区域，并使用最大类间方差(Maximum between-cluster Variance, OTSU)算法进行目标和噪声点快速提取；最后使用多帧叠加，剔除噪声点，最终提取出恒星目标。实验结果表明，该算法计算简单，运行时间短，同时具有较高的检测率。该算法能够在复杂的背景中有效地检测出恒星目标，虚警率较低。

The extraction of navigation stars is a critical step in near-infrared celestial navigation. It is related to the subsequent star target identification and star image matching directly. Because of the strong background of the sky, the extraction of star targets is extremely difficult. If the near-infrared celestial navigation is used to detect stars in the near-infrared waveband, enough star targets for navigation can be acquired even in the daytime. On the basis of analysis of the characteristics of near-infrared star images, an energy projection method is introduced and the potential star targets and noises are located according to the peak point of the projection. Then, the areas to be processed are set up according to the energy variation. The targets and noise points are extracted quickly by suing the OTSU algorithm. Finally, after the multi-frame overlay is used to remove the noise points, the star targets are extracted. The experimental result shows that this algorithm is simple in calculation, short in operation time and higher in detection ratio. It can detect the star targets against a complex background effectively with a low false alarm rate.