视轴指向校正是红外监视系统目标高精度跟踪定位的重要前提，而扫描相机视轴指向校正又是其中的难点。在分析扫描相机成像模型及其特点的基础上，提出基于失配角估计的视轴指向校正原理模型。通过建立失配角状态转移模型和视轴指向观测模型，并采用无迹卡尔曼滤波器(UKF)，实现了对失配角参数的实时估计和视轴指向的实时校正。仿真结果表明，所提算法对相机视轴指向的校正精度高、性能稳定，可有效提高红外监视系统目标跟踪处理的实时性能和精度。

Line of sight (LOS) calibration is the key precondition of accurate location and tracking of targets in infrared surveillance systems and the LOS calibration of scanning sensor is one of the difficulties. Based on the analysis of the imaging model and characteristics of scanning sensor, a theoretical calibration model based on the estimation of mismatching angles is proposed. By establishing the process model of the mismatching angles and the observation model of sensor LOS, and using an unscented Kalman filter (UKF), the real time estimation of mismatching angles and calibration of sensor LOS are finally achieved. Simulation results show that the proposed algorithm has a high precision and smooth performance for sensor LOS calibration, and can effectively improve the timeliness and precision of target tracking process in infrared surveillance system.