针对靶场现场监测范围大,相机焦距不固定,相机空间位置及角度各不相同的情况,为实现对弹落点空间坐标位置的高精度自动测量,提出了一种在野外大视场环境下使用的基于单相机空间坐标测量系统的快速标定方法.首先,在小孔成像模型的基础上,通过GPS测量获得视场内两个标定点及相机在大地坐标系中的坐标;然后读取标定点的像素坐标,根据对角相等及最小二乘法实现焦距与旋转矩阵的分步标定;最后在保证标定精度前提下,略去主点的标定过程,确定相机主点为理想主点位置.实验结果表明,在测试距离1 km以外,对视场宽度为200m的区域进行监测时,校验点相对定位误差低于0.25％.该相机标定方法不需要高精度靶标,操作简单,适用于野外大视场环境下单相机空间坐标测量系统的快速标定.%In order to realize the high-precision and automatic measurement of space coordinate position for the bomb falling point in the wildly large field of view,the space coordinate measurement system of the single camera was established.Aiming at the large scope of on-site monitoring for shooting range,flexible focal distance of camera,different spatial position and angle of camera,a fast calibration method which was used in the wildly large field of view was proposed.Firstly,on the basis of the pinhole imaging model,taking advantages of the GPS measurement,two calibration points within the field of view and the coordinate of the camera in the geodetic coordinate system was obtained;and the pixel coordinate of calibration points were read;according to the equality of opposite angles and the least square method,the sub-step calibration of the focal distance and the rotation matrix was realized.On the premise of ensuring the calibration accuracy,the calibration process of the principal point was omitted;and the principle point of the camera was determined to be the ideal position for the principle point.The experimental result shows that beyond 1km of testing distance,at the time of monitoring the area with 200m width of field,the relative calibration error of the check point is lower than 0.25％.The camera calibration method does not need high-precision target,because it is easy to be operated and is applicable to fast calibration for the space coordinate measurement system of the single camera under the environment of the wildly large field of view.
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