红外面阵旋转搜索系统因其系统结构简单、灵活性高、成本较线阵低等优点备受关注。在红外面阵旋转搜索系统中，复杂背景下的弱小目标检测是一个难题。为了有效抑制背景干扰，降低复杂背景带来的虚警，针对红外面阵旋转扫描系统的成像特性，提出了基于线目标特征加权的恒虚警检测算法。首先，通过背景抑制和阈值分割初步得到离散的潜在目标点迹图。其次，研究分析了线目标的三类特征，并对各类特征进行量化和加权处理，从而得到总的加权值；最后，将加权值映射到离散的点迹图上，得到关于加权值的图像序列，再通过恒虚警检测方法得到新的分割阈值，达到二次分割的目的，从而抑制背景干扰、减少虚警和误判。实验结果表明：该方法可以显著地减少红外面阵旋转搜索系统中复杂背景造成的虚警，并保证能够有效检测出弱小目标。

Infrared focal plane array rotation search system catches attention because of simple system structure, high flexibility and low cost compared with the linear array search system. The dim-small target detecting technology under complex background is a difficult subject in infrared focal plane array rotation search system. In order to effectively suppress background noise and reduce false alarm caused by complex background, constant false alarm rate algorithm based on weighted feature of linear target was presented aiming at the research of imaging properties of infrared focal plane array rotation system. Firstly, the discrete potential target image was obtained initially by background suppression and threshold segmentation. Next, three characteristics of linear target were analyzed and the total weighted value was calculated by quantifying and weighting. Finally, the weighted value was mapped to the discrete target image and the image sequence about the weighted value was achieved, then a new segmentation threshold obtained by CFAR algorithm was applied to suppress the background interference and reduce false alarm and false positives. The experiment results show that the proposed method can significantly reduce the false alarm caused by the complex background in infrared focal plane array rotation search system and can ensure to detect the dim-small target.