中文摘要：

提出一种利用导引头图像信息进行飞机目标被动定位的方法。该方法以目标可预知的先验几何特征为基础，并基于摄像系统视场较小且目标距离远大于目标尺寸时，成像模型可用弱透视投影近似的事实，推导出借助特征直线估计目标距离的单目视觉算法。与传统的目标定位方法不同，该算法通过特征直线的成像尺寸以及相互夹角反映目标成像姿态的变化，使得目标定位算法不依赖于对目标姿态的估计，提高了不同的空间姿态下目标定位的准确性。实验结果表明，该算法能够在低信噪比情况下准确定位目标，且算法不受目标姿态的影响。

英文摘要：

A novel passive location method is presented by using IR seeker image. As the seeker Field of View （FOV） is small and target distance is much bigger than target size, a monocular algorithm using characteristic lines to estimate target distance is developed based on the fact that the camera model can be described as weak perspective projection. Compared with traditional passive location method, the proposed algorithm utilizes the size and angle of characteristic lines in image to represent the variation of object attitude and the method improves the location precision and makes the location process independent on attitude estimation. Experimental results manifest that the proposed algorithm can locate the target accurately in low SNR, and the algorithm can adapt to the change of attitude.