目前大气透射仪存在发射端和接收端安装调校困难的问题, 并且在工作过程中, 发射端和接收端一旦发生偏移, 光轴不处于一条直线, 将大大影响能见度测量结果。针对这些问题, 提出将近景摄影测量技术应用到大气透射仪的对准系统中, 采用圆形作为人工标志物, 通过图像处理及椭圆最小二乘拟合算法, 计算人工标志物的圆心坐标, 根据标志物的圆心坐标与摄像机镜头的中心坐标的位置关系, 将发射端和接收端的摄像机镜头的中心通过旋转结构拉倒图像中心；由于摄像机与光轴是同轴设计, 所以摄像机镜头对准就是实现了光轴的对准。实验证明, 利用近景摄影测量技术能够实现大气透射仪快速准确对准, 并且能够实时监控保证光轴始终保持一条直线。

At present, it is difficult for installation and adjustment of the transmissometer. When the emitter and receiving end of the transmissometer are offset, the optical axis is not in a straight line, which will greatly affect the visibility measurement results. The close-range photogrammetry technique is applied to the alignment system of the transmissometer to solve this problem. Use of circular as artificial marker, and calculate of central coordinates of artificial markers by image processing and ellipse least squares fitting algorithm. According to the position relationship of the center coordinates of the artificial marker and the center coordinates of the camera lens, The center of the camera lens at the emitter and receiving ends is pulled down the center of the image through a rotating structure. Since the camera and the optical axis are coaxial, the camera lens alignment is to achieve the alignment of the optical axis.Experimental results show that close-range photogrammetry can achieve rapid and accurate alignment of the transmissometert,and it can be monitored in real time to keep the optical axis straight.