捕获、对准、跟踪系统是空间激光通信重要组成部分，是通信正常进行的前提与保障。针对捕获系统中的初始指向内容进行了详细研究，给出初始系统指向系统模型，应用坐标转换矩阵补偿由于位置不同、姿态变化、安装基准轴差异、初始零位不一致等对初始指向方位角和俯仰角的影响。提出初始指向系统视轴标校方法，根据误差分析方法确定了指向精度及捕获不确定区域大小。在飞机飞机动态演示实验中，应用双天线全球定位系统/捷联导航系统(GPS/INS)组合器件实时得到位置、姿态等参数，实现初始指向系统性能测试。借助观靶相机实际测量本系统捕获不确定区域大小为10 mrad，与理论分析结果基本一致。

A cquisition, pointing, and tracking is an important component in space laser communication. It is the premise and guarantee to normal work. Line-of-sight initial alignment is researched in detail and initial alignment model is proposed. Coordinate conversion method is used to solve alignment affect to azimuth and pitch angle, by compensating position change, attitude varying, difference to installation datum, initial zero inconsistent. Calibration method on initial alignment line-of-sight is proposed. Acquisition uncertain area and alignment accuracy are determined according to error theory. In dynamic aircraft to aircraft, the initial alignment performance is tested by using the parameters of position, attitude provided by double antenna global position system/inertial narigation system (GPS/INS). Area of uncertainty measured by observation camera is 10 mrad and it is consistent with theoretical analysis results.